Arches are one of the most fundamental structural and aesthetic elements in architecture. From the semicircular Roman arches of ancient aqueducts to the soaring pointed arches of Gothic cathedrals, and from the ornate horseshoe arches of Islamic mosques to the wide, depressed Tudor arches of English palaces, every architectural style across history has developed its own signature arch type.
Understanding the different types of arches in architecture helps you identify architectural periods, analyse structural systems, and make better design decisions. Whether you are an architecture student preparing for exams, a practising professional, or someone who loves buildings this guide covers every arch type you need to know, with structural notes and real examples for each.
What is an Arch?
An arch is a curved structure made of wedge-shaped units — either bricks or stones, joined with mortar and placed at openings to support the weight of the wall above along with other loads. Because of its curved shape, the loads from above are distributed outward to the supports on either side, called the abutments or piers, rather than straight down like a lintel. This is what gives arches their exceptional load-bearing strength. In simple terms, the meaning of an arch comes down to this: it's a curved structural opening that turns weight into sideways force instead of straight-down pressure.
This is what gives arches their exceptional load-bearing strength. Before diving into the types, it helps to know three key terms used across all arch types. The keystone is the wedge-shaped stone at the very top centre of the arch, it is placed last during construction and locks everything in place.
Voussoirs are the individual wedge-shaped blocks that make up the arch body. The impost is the projecting block at the top of a column or wall where the arch begins to spring. For a deeper understanding of these terms and how they work together structurally, read our detailed guide on arch anatomy.
The common terms used in arches are
Keystone: A keystone (or capstone) is a wedge-shaped stone at the apex of a masonry arch or typically round-shaped one at the apex of a vault.
Voussoir: A voussoir is a wedge-shaped stone used in building arches and vaults.
Impost: An impost or impost block is a projecting block resting on top of a column or embedded in a wall, serving as the base for the springer or lowest voussoir of an arch.
The 4 Main Types of Arches in Architecture
While there are over 20 recognised arch types used in architecture and construction, all of them fall under 4 primary categories that every architecture student must know.
The first is the Round Arch: also called the semicircular arch, which was developed and perfected by the Romans. It forms a perfect half circle and distributes load evenly to both sides, making it one of the most stable arch forms ever used.
The second is the Pointed Arch: which is the defining feature of Gothic architecture, two arcs meet at a sharp apex at the top, directing load more vertically and allowing for taller, thinner walls and much larger windows.
The third is the Segmental Arch: which is a circular arc of less than 180 degrees. It is widely considered the strongest arch type for resisting horizontal thrust, which is why it has been the preferred choice for bridges for centuries.
The fourth is the Flat Arch: which appears horizontal but contains a slight internal rise. It is used where minimum headroom is needed above an opening and where the loads above are not excessively heavy.
Every other arch type you will encounter — Tudor, Ogee, Horseshoe, Trefoil, Lancet, Multifoil, Parabolic — is either a variation, a combination, or a decorative development of these four foundational forms.
The Different Types of Arches Are
1. Round Arch
Also known as a semi-circular arch, this is formed in a continuous curve and was developed by the Romans. They were often used side by side in a series to create an arcade. The ancient Romans often used circular or rounded arches to build bridges, large buildings, and aqueducts.
The round arch was the structural backbone of the Roman Empire. Roman engineers used it to build bridges, aqueducts, amphitheatres, and triumphal arches across their entire empire structures that have survived over two thousand years. The key reason for this durability is that the semicircular form creates pure compression forces throughout the arch, with no bending stress, meaning every stone in the arch is being squeezed together rather than pulled apart. This also makes the round arch forgiving in construction. Small errors in stone cutting can be compensated by mortar without weakening the structure significantly. To understand how Roman arch techniques directly influenced medieval European architecture, read our article on Romanesque vaulting and buttressing.
Illustrations: Sonali
2. Segmental Arch
The segmental arch is one of the strongest arch types in construction because of its superior ability to resist horizontal thrust, the outward force that pushes the arch's supports apart and causes structural failure. Its shallow, low-rise curve means more of the applied load is transferred sideways to the abutments rather than downward through the arch, making it exceptionally stable under heavy loads over wide spans. This is why the segmental arch became the dominant choice for bridge construction from the medieval period onwards and why it remains widely used in modern civil engineering today. If you want to understand how arches function in bridge engineering specifically, our article on arch bridges covers this in depth.
Civil engineers who work with arch structures in bridges, tunnels and infrastructure increasingly model and coordinate these systems in BIM environments. Kaarwan's BIM Certification for Civil Engineers is specifically designed for this.
Illustrations: Sonali
3. Flat Arch
A spanning member constructed of mutually supporting voussoirs and having straight or almost straight horizontal intrados and extrados. The flat arch generates an equilateral triangle within Intrados as a basis at an angle of 60° degrees. The flat arch is commonly used for building structures with minimum weight requirements.
Illustrations: Sonali
4. Triangular Arch
Two flat stones set at an angle of 45° or thereabouts, mitered at the top, and touching each other at the apex of a triangular-headed opening. Triangular arches are strong and stable, and they can support a lot of weight. They are also relatively easy to build, which makes them a popular choice for architects and builders.
Illustrations: Sonali
5. Rounded horse-shoe Arch
Also called the Moorish arch and the keyhole arch, is a type of arch in which the circular curve is continued below the horizontal line of its diameter so that the opening at the bottom of the arch is narrower than the arch's full span. In addition to their use across the Islamic world, horseshoe arches became popular in Western countries in Moorish Revival architecture, which became fashionable in the 19th century. They were widely used in Moorish Revival synagogues.
Illustrations: Sonali
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6. Multifoil Arch
A multifoil arch, also known as a cusped arch, polylobed arch, or scalloped arch, is an arch characterized by multiple circular arcs or leaf shapes that are cut into its interior profile or intrados.The multifoil arch is found most prominently in Islamic architecture, particularly in mosques, palaces and tombs, where it serves both a structural and deeply decorative purpose.
They are also used in some secular buildings, such as palaces and tombs. Rounded multifoil arches are known for their beauty and their intricate design. The interlocking circular lobes of the multifoil profile create visual rhythm and complexity that became a signature of Moorish and Andalusian architectural identity — seen most famously in the Great Mosque of Córdoba and the Alhambra Palace in Spain. Beyond aesthetics, multifoil arches distribute dynamic loads across multiple curve segments, which gives them an engineering advantage in managing lateral forces and seismic stress. For a full structural analysis of why architects continue choosing this arch form in modern construction
Read our dedicated article: The Structural Advantages of Multifoil Arch Construction
Illustrations: Sonali
7. Trefoil Arch
A trefoil arch, or three-foiled cusped arch, is an arch incorporating the shape or outline of a trefoil – three overlapping circles. It has been widely used for its symbolic significance in Christian architecture. Trefoil arches are common in Gothic architecture for portals and decoration. It was adopted as ornamentation to churches during the Middle Ages.
Illustrations: Sonali
8. Ogee four-centered Arch
A four-centered arch is a low, wide type of arch with a pointed apex. Its structure is achieved by drafting two arcs which rise steeply from each springing point on a small radius, and then turning into two arches with a wide radius and much lower springing point. It is a pointed sub-type of the general flattened depressed arch. This type of arch uses space efficiently and decoratively when used for doorways.
Illustrations: Sonali
9. Pointed trefoil Arch
The pointed trefoil arch is a distinctive architectural form that has been used in the construction of many structures throughout history. This particular form of arch is composed of three lobes that are connected at the peak of the arch. The lobes of the arch are slightly pointed and typically built from stone or brick. This form of arch is often used in Gothic architecture and is particularly suited to the construction of vaults and ceilings.
The pointed arch is the single most important architectural innovation of the medieval period. Unlike the round arch, which requires thick walls and heavy buttressing to contain the outward thrust, the pointed arch directs a much greater proportion of the load vertically downward. This meant Gothic architects could build dramatically taller walls, make those walls significantly thinner, and fill them with enormous stained glass windows none of which would have been possible with Roman semicircular arches. The pointed arch is not one specific shape but a family of forms including the lancet arch, the equilateral arch, and the drop arch, each defined by the relationship between the radius of the arcs and the width of the opening. Gothic architecture relied almost entirely on this arch family to achieve its characteristic soaring verticality. To explore how pointed arches shaped the complete Gothic architectural system including ribbed vaults and flying buttresses, read our article Key Characteristics of Gothic Architecture Page.
Illustrations: Sonali
10. Lancet Arch
The lancet arch is a variety of pointed arch in which each of the arcs, or curves, of the arch have a radius longer than the width of the arch. It takes its name from being shaped like the tip of a lance. The lancet window is one of the typical features of the Early English 13th century in Gothic architecture.
Illustrations: Sonali
11. Tudor Arch
A four-centered arch, the inner pair of curves having a radius much greater than that of the outer pair. The Tudor arch was especially used for doorways, where it gives a wide opening without taking too much space above, compared to a more pointed Gothic arch. In Tudor architecture of the grander sort, it is so used when the window openings are rectangular, for example at Hampton Court Palace.
Illustrations: Sonali
12. Inflexed Arch
An inflexed or reversed ogee arch is a unique design that takes the arcs of a pointed arch and inverts them to create two bows in the opening. The inverted design of the apex of the archway creates a serpentine appearance, adding architectural appeal and style. This arch design is a common aesthetic feature in architecture, and modern design incorporates the inflexed arch for a variety of building applications.
Illustrations: Sonali
13. Parabolic Arch
Parabolic arch follows the mathematical curve of a parabola rather than a circular arc. It is the most structurally efficient arch shape for uniformly distributed loads because the bending moment along the entire arch is theoretically zero, meaning every part of the structure experiences only pure compression with no bending stress at all. This makes the parabolic arch ideal for very large spans where minimising material while maximising structural efficiency is the priority.
The most famous example in the world is the Gateway Arch in St. Louis, USA, which stands 192 metres tall and is constructed entirely in stainless steel following a weighted catenary curve that approximates a parabola. Parabolic arches are commonly used in modern long-span bridges, sports stadiums, aircraft hangars, and large industrial roof structures.
Architects and engineers designing complex arch geometries like parabolic forms use parametric tools to control and optimise the curve. Kaarwan's Advanced Rhino and Grasshopper Parametric Design Course teaches exactly how to generate and refine these geometries computationally.
14. Elliptical Arch
An elliptical arch forms a curve resembling an ellipse wider and flatter than a semicircle. It creates an elegant, elongated opening that gives a sense of graceful width rather than the height associated with pointed or semicircular arches. Elliptical arches were a favourite in Renaissance and Baroque architecture, where the relationship between aesthetic refinement and structural function was a primary design concern. They are commonly found in grand entrances, large window openings, and decorative facades of palaces and civic buildings from the 15th to 18th centuries.
Constructing a true elliptical arch requires more precision than a semicircular one because the curve radius changes continuously rather than remaining constant, but the visual result is considered more sophisticated and harmonious in proportion.
15. Relieving Arch
A relieving arch, also called a discharging arch, is a structural arch built above a flat arch, a wooden lintel, or a weaker opening in order to redirect the load around the vulnerable element below. It acts as a load bypass, the arch above absorbs and transfers the weight from the wall to the supports on either side, meaning the lintel or flat arch below carries only its own weight rather than the full load of the wall above it. Relieving arches are an engineering solution rather than an aesthetic feature and are often hidden inside walls or plastered over, making them invisible in the finished building. They are found extensively in ancient Roman construction, medieval churches, and historic brick buildings where the original lintels had decayed or were not strong enough to carry increased loads.
16. Stilted Arch
A stilted arch is a semicircular arch that has vertical straight sections at the springing points before the curve begins. Instead of the arch curving immediately from the impost, it rises vertically for a short distance and then transitions into the circular arc. This raises the crown of the arch to a greater height than a standard semicircular arch would allow for the same span width, which is useful when greater ceiling height or visual proportion is needed above an opening without widening the opening itself.
Stilted arches are characteristic of Byzantine and early Romanesque architecture and can be found in early Christian basilicas across Italy and the Eastern Mediterranean. They represent one of the earliest attempts by architects to manipulate arch geometry to achieve both structural and proportional goals simultaneously.
Understand how arch types shape facade design decisions in Facade Design Masterclass for Students and Architects page.
Which Arch is the Strongest
Architects and engineers are often asked which arch type is the strongest, and the answer depends on what type of load and structural challenge is being addressed. For resisting horizontal thrust — the outward force that pushes supports apart — the segmental arch is the strongest because its shallow curve transfers more load sideways to the abutments. For resisting evenly distributed vertical loads, the semicircular Roman arch is considered most stable because it creates pure compression throughout with no bending forces.
For tall structures requiring load to travel vertically with minimal outward thrust, the pointed Gothic arch performs best. And for maximum structural efficiency across a very large span with minimum material, the parabolic arch is the engineering benchmark. The right arch is always the one matched to its specific structural and spatial requirement.
Arches Classified by Material
Shape aside, arches also get sorted by what they're actually built from — and this isn't just a trivia distinction. The material decides how the voussoirs get cut and joined, and honestly, it caps how far the arch can span before it's asking for trouble.
Stone Arches - Stone arches lean on precisely cut wedge units called voussoirs — either finely dressed ashlar stone for the monumental stuff, or rougher rubble stone when the opening's smaller and more forgiving. Ashlar arches, cut with those tight, almost mortar-thin joints, were basically the Roman standard for aqueducts and bridges. Makes sense — that precision is what kept compression forces distributing evenly through the whole arch. Rubble stone arches went the opposite direction: irregular stones, thicker mortar beds, common wherever exact geometry wasn't the priority — think vernacular builds, lower-load openings.
Brick Arches - Brick arches come in a few flavours — standard rectangular bricks, axed bricks (cut into wedge shapes right on site), or purpose-made gauged bricks manufactured with a taper built in. Gauged brick arches are the ones you associate with fine Georgian and Victorian brickwork — they allow for razor-thin mortar joints and a curve that's just cleaner than what standard brick can pull off. And brick arches haven't gone anywhere, honestly — still the go-to for door and window openings today because bricks are simply easier to source, cut, and lay into a curve than dressed stone.
Concrete Arches - Concrete arches show up two ways: precast, where units are cast off-site to a fixed curve and then assembled on site, or monolithic, poured in place as one continuous structure using formwork. Monolithic concrete — usually reinforced with steel — is what modern large-span structures lean on, bridges, industrial roofs, that kind of thing, since concrete doesn't hit the same size ceiling that individual stone or brick units do. It's also exactly why parabolic and segmental arches at very large spans (see the Parabolic Arch section above) are almost always built in reinforced concrete or steel rather than masonry.
If you want to take your understanding of architectural structures, construction systems and design principles into real professional practice, Kaarwan's architecture courses teach you how to apply this knowledge using industry tools including Revit, AutoCAD, Rhino and Grasshopper — all taught by practising architects and engineers. Browse all architecture courses.
FAQs
1. What is the purpose of keystones in an arch?
Keystones serve as the central, wedge-shaped stone at the apex of a masonry arch. They distribute pressure and help hold the other stones in place, providing structural integrity to the arch.
2. Why is a segmental arch considered one of the strongest arch types?
A segmental arch is strong because it can resist thrust effectively due to its circular arc, which is less than 180 degrees. This shape ensures that more of its load is delivered sideways to the abutments.
3. What distinguishes the lancet arch from other pointed arches?
The lancet arch features a longer arc radius compared to the width of the arch, giving it a slender, lance-like appearance. It is commonly associated with Early English Gothic architecture.
4. How does the multifoil arch enhance architectural design?
Multifoil arches are characterized by multiple circular arcs or leaf shapes within the arch's profile. They add intricate and decorative designs, often found in mosques, religious buildings, and some secular structures like palaces.
5. What are the 4 main types of arches in architecture?
The 4 main types of arches are the round or semicircular arch developed by the Romans, the pointed arch which defines Gothic architecture, the segmental arch which is the strongest for resisting horizontal thrust, and the flat arch used where minimum headroom is needed. All other arch types are variations or combinations of these four foundational forms.
6. Which type of arch is the strongest?
The segmental arch is considered the strongest for resisting horizontal thrust, making it the dominant choice for bridge construction. The semicircular Roman arch is the strongest for evenly distributed vertical loads. For tall structures with minimal outward thrust, the pointed Gothic arch is the most efficient. Each arch type is strongest in its specific structural context.
7. What is the difference between a Gothic arch and a Roman arch?
Roman arches are semicircular, the curve forms a perfect half circle and distributes load evenly outward to both sides. Gothic arches are pointed two arcs meet at a sharp apex and direct load more vertically downward. This difference meant Gothic architects could build dramatically taller and thinner walls with far larger windows than Roman architecture ever achieved.
8. What is a series of arches called?
A continuous series of arches supported by columns or piers is called an arcade. When arches are built into a wall purely for decoration rather than as open passageways, they are called blind arcades. The arcade was a defining feature of Roman, Romanesque, Byzantine, and Gothic architecture.
9. What is the stone at the top of an arch called?
The central stone at the very top of an arch is called the keystone. It is always placed last during construction and locks all the surrounding wedge-shaped stones called voussoirs in place. Without the keystone the arch cannot stand. The keystone redirects compression forces from both sides of the arch and transfers them downward through the structure to the supports.
10.What is the difference between a flat arch and a segmental arch?
A flat arch appears horizontal but has a very slight internal rise of 10 to 15 millimetres per metre of width to allow for minor settlement. A segmental arch has a clearly visible curve, it is a circular arc of less than 180 degrees. Segmental arches are significantly stronger and better at resisting outward thrust. Flat arches are used where clearance above an opening is very restricted and loads are relatively light.
11. What type of arch is used in Islamic architecture?
Islamic architecture primarily uses the horseshoe arch, the pointed arch, and the multifoil arch. The horseshoe arch where the curve extends below the springing line making the opening narrower at the bottom than at its widest point is the most characteristic feature of Islamic and Moorish architecture. The multifoil arch with its multiple scalloped lobes is found in mosques, palaces, and important civic buildings including the Alhambra in Granada and the Great Mosque of Córdoba.
These were some of the important points to remember while learning about arches in buildings. Stay tuned for more information on other important topics in the AEC industry and follow Kaarwan for such detailed guides!
