Free Tool · Architects and Designers
Unit Converter for Architects and Designers
Convert between mm, cm, m, inches, and feet instantly. Free metric-imperial unit converter for architects, interior designers, and product designers. No sign-up required.
Enter a value above to see all conversions.
Click a unit to set it as the input unit:
Common Architectural Dimensions
Metric and imperial standards are not just conversions of each other. They are independently established norms. Both tables are shown separately so you can see the actual standards used in each system.
Metric System
| Dimension | mm | cm | m | in | ft–in |
|---|---|---|---|---|---|
| Standard door height Typical residential interior door | 2100 | 210 | 2.1 | 82.7 | 6′10.7″ |
| Standard ceiling height Minimum comfortable ceiling height | 2400 | 240 | 2.4 | 94.5 | 7′10.5″ |
| Standard door width Single hinged door, residential | 900 | 90 | 0.9 | 35.4 | 2′11.4″ |
| Stair riser height Standard comfortable step rise | 180 | 18 | 0.18 | 7.1 | 0′7.1″ |
| Stair tread depth Minimum comfortable tread depth | 280 | 28 | 0.28 | 11 | 0′11″ |
| Kitchen counter height Standard worktop height | 900 | 90 | 0.9 | 35.4 | 2′11.4″ |
| Typical room width Minimum comfortable bedroom width | 3600 | 360 | 3.6 | 141.7 | 11′9.7″ |
| Standard brick length Standard EU/UK metric brick | 215 | 21.5 | 0.215 | 8.5 | 0′8.5″ |
Imperial System
| Dimension | ft–in | in | mm | cm | m |
|---|---|---|---|---|---|
| Standard door height Standard North American interior door | 6′8″ | 80 | 2032 | 203.2 | 2.032 |
| Standard ceiling height Typical residential floor-to-ceiling | 8′0″ | 96 | 2438 | 243.8 | 2.438 |
| Standard door width Standard residential interior door | 2′8″ | 32 | 813 | 81.3 | 0.813 |
| Stair riser height Typical comfortable step rise | 7″ | 7 | 178 | 17.8 | 0.178 |
| Stair tread depth Typical comfortable tread depth | 11″ | 11 | 279 | 27.9 | 0.279 |
| Kitchen counter height Standard US countertop height | 3′0″ | 36 | 914 | 91.4 | 0.914 |
| Typical room width Minimum comfortable bedroom width | 10′0″ | 120 | 3048 | 304.8 | 3.048 |
| Standard brick length Standard US modular brick | 7⅝″ | 7.625 | 194 | 19.4 | 0.194 |
- Divide millimeters by 25.4 to get inches. For example, 100mm ÷ 25.4 = 3.937 inches. Alternatively, multiply by 0.03937. This converter does it automatically — enter your value in mm and see the inch equivalent instantly.
- There are exactly 304.8 millimeters in one foot. One foot equals 12 inches, and one inch equals 25.4mm, so 12 × 25.4 = 304.8mm. This is a key conversion for architects working between metric and imperial systems.
- Most countries use metric units — millimeters (mm) and meters (m) are the standard in architecture. The UK uses a mix of metric and imperial. The USA primarily uses feet and inches. When sharing drawings internationally or specifying imported fixtures and materials, unit conversion is essential.
- Multiply feet by 30.48 and inches by 2.54, then add the results. For example, 6 feet 2 inches = (6 × 30.48) + (2 × 2.54) = 182.88 + 5.08 = 187.96 cm. This converter handles single-unit conversions — enter feet as a decimal (e.g., 6.167 ft for 6 ft 2 in).
- Architectural projects frequently involve both metric and imperial measurements in the same workflow — client briefs, imported building products, international standards, and legacy drawings may all use different unit systems. Quick, accurate conversion prevents costly errors in drawings and specifications.
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