Printable Worksheet
Length Reference Card - Pocket Metric/Imperial Cheat Sheet
Printable pocket reference card for length conversions. Metric and imperial side-by-side. Includes common objects for intuition.
Length Reference Card - Pocket Metric/Imperial Cheat Sheet
Cut along the dotted lines, fold in half, and carry this card in your wallet or toolbox. It is a quick-reference for everyday length conversions.
Metric to Imperial
| Metric | Imperial |
|---|---|
| 1 mm | 0.04 in |
| 1 cm | 0.39 in |
| 1 m | 3.28 ft |
| 1 km | 0.62 mi |
| 10 mm | 0.39 in |
| 10 cm | 3.94 in |
| 10 m | 32.8 ft |
| 10 km | 6.21 mi |
Imperial to Metric
| Imperial | Metric |
|---|---|
| 1 in | 2.54 cm |
| 1 ft | 30.48 cm |
| 1 yd | 0.91 m |
| 1 mi | 1.61 km |
| 6 in | 15.24 cm |
| 12 in (1 ft) | 30.48 cm |
| 100 ft | 30.48 m |
| 1 mi | 1.61 km |
Intuition: Common Objects
| Object | Length |
|---|---|
| Paperclip | ~33 mm |
| Standard pencil (new) | ~19 cm |
| Sheet of paper (US Letter) | 28 cm |
| Sheet of paper (A4) | 29.7 cm |
| Doorway (US standard) | 6 ft 8 in / 2.03 m |
| Basketball court (length) | 28 m |
| Football field (incl. end zones) | 110 m |
| Marathon | 42.195 km / 26.2 mi |
| Earth diameter | 12,742 km / 7,918 mi |
Quick Mental Math
- Inches to cm: multiply by 2.54 (or: cm = in × 2.5, close enough)
- Feet to meters: multiply by 0.305 (or: divide by 3)
- Miles to km: multiply by 1.6 (or: mi × 1.5, close enough)
- cm to inches: divide by 2.54 (or: cm ÷ 2.5)
Temperature (Bonus)
Most Americans know 32°F = 0°C and 212°F = 100°C. The mental shortcut:
- F to C: subtract 30, divide by 2. Example: 70°F → (70-30)/2 = 20°C (actual 21.1°C)
- C to F: multiply by 2, add 30. Example: 20°C → 20×2+30 = 70°F (actual 68°F)
For more, use the Fahrenheit to Celsius converter.