Metric & Imperial Conversion Guide
A quick reference for reading part specs, chemical volumes, and equipment dimensions across metric and imperial. Keep it bookmarked — or send us the spec and we'll sort it out with your quote.
Shop-Floor Staples
| Unit | Equivalent | How to Convert |
|---|---|---|
| 1 inch (in) | 25.4 millimeters (mm) | in to mm: multiply by 25.4 (exact) |
| 1 foot (ft) | 0.3048 meters (m) | ft to m: multiply by 0.3048 |
| 1 pound (lb) | 0.4536 kilograms (kg) | lb to kg: multiply by 0.4536 · kg to lb: multiply by 2.205 |
| 1 ounce (oz) | 28.35 grams (g) | oz to g: multiply by 28.35 |
| 1 US gallon (gal) | 3.785 liters (L) | gal to L: multiply by 3.785 |
| 1 fluid ounce (fl oz) | 29.57 milliliters (mL) | fl oz to mL: multiply by 29.57 |
| Temperature | °F = (°C × 9/5) + 32 | °C = (°F − 32) × 5/9 |
Common fastener sizes: 1/4" = 6.35 mm · 3/8" = 9.525 mm · 1/2" = 12.7 mm · 3/4" = 19.05 mm · 1" = 25.4 mm
Metric Length
| Unit | Equivalent | How to Convert |
|---|---|---|
| 1 kilometer (km) | 1,000 meters (m) | km to m: multiply by 1,000 |
| 1 meter (m) | 100 centimeters (cm) | m to cm: multiply by 100 |
| 1 meter (m) | 1,000 millimeters (mm) | m to mm: multiply by 1,000 |
| 1 centimeter (cm) | 10 millimeters (mm) | cm to mm: multiply by 10 |
| 1 centimeter (cm) | 0.01 meters (m) | cm to m: divide by 100 |
| 1 millimeter (mm) | 0.001 meters (m) | mm to m: divide by 1,000 |
| 1 kilometer (km) | 100,000 centimeters (cm) | km to cm: multiply by 100,000 |
Imperial Length and Metric Equivalents
| Unit | Equivalent | How to Convert |
|---|---|---|
| 1 mile (mi) | 1,760 yards (yd) | mi to yd: multiply by 1,760 |
| 1 mile (mi) | 1.609 kilometers (km) | mi to km: multiply by 1.609 |
| 1 yard (yd) | 0.9144 meters (m) | yd to m: multiply by 0.9144 |
| 1 yard (yd) | 3 feet (ft) | yd to ft: multiply by 3 |
Weight / Mass
| Unit | Equivalent | How to Convert |
|---|---|---|
| 1 kilogram (kg) | 1,000 grams (g) | kg to g: multiply by 1,000 |
| 1 gram (g) | 1,000 milligrams (mg) | g to mg: multiply by 1,000 |
| 1 gram (g) | 0.001 kilograms (kg) | g to kg: divide by 1,000 |
Volume
| Unit | Equivalent | How to Convert |
|---|---|---|
| 1 liter (L) | 1,000 milliliters (mL) | L to mL: multiply by 1,000 |
| 1 milliliter (mL) | 0.001 liters (L) | mL to L: divide by 1,000 |
| 1 milliliter (mL) | 1 cubic centimeter (cm³) | 1 mL = 1 cm³ exactly |
Everyday Reference Points
Length: a paper clip is about 3 cm (30 mm) long · a basketball player might be 2 m tall (200 cm) · a football field is 100 yards, about 91.44 meters.
Weight: a paperclip weighs about 1 gram · a textbook might weigh 2 kg (2,000 g) · an apple weighs about 200 g (0.2 kg).
Volume: a can of soda is 355 mL (0.355 L) · a standard water bottle holds 500 mL (0.5 L).
Metric Prefix System
| Prefix | Symbol | Value | Example |
|---|---|---|---|
| kilo- | k | 1,000 | 1 km = 1,000 m |
| hecto- | h | 100 | 1 hm = 100 m |
| deca- | da | 10 | 1 dam = 10 m |
| (base unit) | — | 1 | 1 m, 1 g, 1 L |
| deci- | d | 0.1 (1/10) | 1 dm = 0.1 m |
| centi- | c | 0.01 (1/100) | 1 cm = 0.01 m |
| milli- | m | 0.001 (1/1000) | 1 mm = 0.001 m |
Conversion tip: when converting between metric units, count the steps in the prefix system — moving right (to smaller units) multiply by 10 per step; moving left (to larger units) divide by 10 per step. Example: meters to millimeters is 3 steps right, so multiply by 10³ (1,000).
Need a part in a spec you've only got in the other system? Request a quote — 803-265-2511.