Convert lengths between millimetres, centimetres, inches and feet for pan sizes and kitchen measurements.
Usage Tip
When swapping pan sizes, match the area, not just one dimension.
Inches and centimetres at a glance
Common length conversion tables
Inches ↔ centimetres
| Inches | Centimetres |
|---|---|
| 1/4 in | 0.6 cm |
| 1/2 in | 1.3 cm |
| 1 in | 2.5 cm |
| 6 in | 15.2 cm |
| 12 in | 30.5 cm |
Feet ↔ metres
| Feet | Metres |
|---|---|
| 1 ft | 0.30 m |
| 3 ft | 0.91 m |
| 6 ft | 1.83 m |
| 10 ft | 3.05 m |
Yards ↔ metres
| Yards | Metres |
|---|---|
| 1 yd | 0.91 m |
| 5 yd | 4.57 m |
| 10 yd | 9.14 m |
| 100 yd | 91.4 m |
Miles ↔ kilometres
| Miles | Kilometres |
|---|---|
| 1 mi | 1.61 km |
| 5 mi | 8.05 km |
| 10 mi | 16.1 km |
| 26.2 mi | 42.2 km |
Most common length conversions
Inches to centimetres
Multiply inches by 2.54. So 9 inches is 22.9 cm and 12 inches (1 foot) is 30.5 cm.
Centimetres to inches
Divide centimetres by 2.54. So 10 cm is about 3.94 inches and 30 cm is about 11.8 inches.
Feet to metres
Multiply feet by 0.3048. So 6 feet is 1.83 m and 10 feet is 3.05 m.
Miles to kilometres
Multiply miles by 1.609. So 5 miles is 8.05 km and a marathon (26.2 mi) is 42.2 km.
Conversion formulas
| Conversion | Formula |
|---|---|
| Inches to cm | cm = inches × 2.54 |
| cm to inches | inches = cm ÷ 2.54 |
| Feet to metres | m = feet × 0.3048 |
| Yards to metres | m = yards × 0.9144 |
| Miles to km | km = miles × 1.609 |
Metric vs US customary units
The United States uses customary units – inches, feet, yards and miles – while most of the world uses the metric system of centimetres, metres and kilometres. The inch is officially defined as exactly 2.54 cm, so these conversions are exact rather than approximate; any small differences you see come only from rounding.
Cooking and baking examples
Pan dimensions
A 9×13 inch baking pan is about 23×33 cm. A 9×5 inch loaf tin is roughly 23×13 cm.
Cake pan sizes
Round tins convert as 8 in = 20 cm, 9 in = 23 cm, and 10 in = 25 cm.
Rolling dough thickness
Thin cookies roll to about 1/8 in (3 mm), standard pastry to 1/4 in (6 mm), and a thicker biscuit dough to about 3/8 in (10 mm).
Pizza diameter
A 12 inch pizza is about 30 cm, a 14 inch is 36 cm, and a 16 inch is 41 cm.
Fraction reference
| Inches | Millimetres |
|---|---|
| 1/8 in | 3 mm |
| 1/4 in | 6 mm |
| 3/8 in | 10 mm |
| 1/2 in | 13 mm |
| 3/4 in | 19 mm |
| 1 in | 25 mm |
Printable length conversion chart
| Inches | cm | mm |
|---|---|---|
| 1 in | 2.5 cm | 25 mm |
| 2 in | 5.1 cm | 51 mm |
| 3 in | 7.6 cm | 76 mm |
| 4 in | 10.2 cm | 102 mm |
| 6 in | 15.2 cm | 152 mm |
| 8 in | 20.3 cm | 203 mm |
| 9 in | 22.9 cm | 229 mm |
| 10 in | 25.4 cm | 254 mm |
| 12 in | 30.5 cm | 305 mm |
Frequently asked questions
Related cooking converters
Accuracy tips
- The inch-to-cm factor (2.54) is exact; rounding only appears when you shorten the decimals.
- For baking pans, match the closest standard size rather than an exact decimal – pans are sold in round numbers.
- When precision matters (woodworking, sewing), keep one or two extra decimal places before rounding.