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Kilometer = 0.621 miles. Kilogram = 2.205 pounds. Liter = 0.264 gallons. Celsius = (F - 32) x 5/9. Here is every metric-to-imperial conversion you will need in one cheat sheet.
This page is designed to be a single reference you can bookmark or print. Every common metric-to-imperial conversion is here, organized by category, with exact values and mental math shortcuts. Use this alongside our unit converter for instant calculations on any value.
| Metric | Imperial | Multiply By | Quick Estimate |
|---|---|---|---|
| 1 millimeter | 0.0394 inches | x 0.0394 | ~25 mm per inch |
| 1 centimeter | 0.3937 inches | x 0.394 | ~2.5 cm per inch |
| 1 meter | 3.281 feet | x 3.281 | ~3.3 feet (a large step) |
| 1 meter | 1.094 yards | x 1.094 | ~1 yard plus a bit |
| 1 kilometer | 0.621 miles | x 0.621 | ~0.6 miles (multiply by 6, divide by 10) |
| 1 inch | 2.54 cm | x 2.54 | ~2.5 cm |
| 1 foot | 30.48 cm | x 30.48 | ~30 cm |
| 1 yard | 0.914 meters | x 0.914 | ~0.9 meters |
| 1 mile | 1.609 km | x 1.609 | ~1.6 km |
| Metric | Imperial | Multiply By | Quick Estimate |
|---|---|---|---|
| 1 gram | 0.0353 ounces | x 0.0353 | ~28 grams per ounce |
| 1 kilogram | 2.205 pounds | x 2.205 | Double + 10% |
| 1 metric ton | 2,205 pounds | x 2,205 | ~2,200 lbs |
| 1 ounce | 28.35 grams | x 28.35 | ~28 grams |
| 1 pound | 0.4536 kg | x 0.4536 | Halve and subtract 10% |
| 1 stone | 6.35 kg | x 6.35 | ~6.4 kg (UK unit, 14 lbs) |
| Metric | Imperial (US) | Multiply By | Quick Estimate |
|---|---|---|---|
| 1 milliliter | 0.0338 fl oz | x 0.0338 | ~30 ml per fl oz |
| 1 liter | 33.814 fl oz | x 33.814 | ~34 fl oz |
| 1 liter | 0.264 gallons | x 0.264 | ~4 liters per gallon |
| 1 liter | 4.227 cups | x 4.227 | ~4 cups per liter |
| 1 liter | 2.113 pints | x 2.113 | ~2 pints per liter |
| 1 liter | 1.057 quarts | x 1.057 | ~1 quart per liter |
| 1 fl oz | 29.574 ml | x 29.574 | ~30 ml |
| 1 cup | 236.6 ml | x 236.6 | ~237 ml |
| 1 pint | 473.2 ml | x 473.2 | ~half a liter |
| 1 gallon | 3.785 liters | x 3.785 | ~3.8 liters |
| Celsius | Fahrenheit | Formula |
|---|---|---|
| -40 C | -40 F | The only point where C = F |
| -18 C | 0 F | Very cold winter |
| 0 C | 32 F | Water freezes |
| 10 C | 50 F | Cool day |
| 20 C | 68 F | Room temperature |
| 30 C | 86 F | Hot day |
| 37 C | 98.6 F | Body temperature |
| 100 C | 212 F | Water boils |
Formula: F = (C x 1.8) + 32. Shortcut: double C, subtract 10%, add 32.
| Metric | Imperial | Multiply By | Quick Estimate |
|---|---|---|---|
| 1 sq meter | 10.764 sq feet | x 10.764 | ~11 sq ft |
| 1 sq kilometer | 0.386 sq miles | x 0.386 | ~0.4 sq miles |
| 1 hectare | 2.471 acres | x 2.471 | ~2.5 acres |
| 1 sq foot | 0.0929 sq meters | x 0.0929 | Divide sq ft by 11 |
| 1 acre | 4,047 sq meters | x 4,047 | ~4,000 sq meters |
| 1 acre | 0.4047 hectares | x 0.4047 | ~0.4 hectares |
| Metric | Imperial | Multiply By | Quick Estimate |
|---|---|---|---|
| 1 km/h | 0.621 mph | x 0.621 | Multiply by 0.6 |
| 1 m/s | 2.237 mph | x 2.237 | ~2.2 mph |
| 1 mph | 1.609 km/h | x 1.609 | ~1.6 km/h |
| 1 knot | 1.852 km/h | x 1.852 | ~1.15 mph |
The metric system was born during the French Revolution in the 1790s, designed to replace the chaotic patchwork of local measurement systems across Europe. Its core principle: every unit relates to others by powers of 10. One kilometer is 1,000 meters. One kilogram is 1,000 grams. One liter is 1,000 milliliters.
Compare that to imperial: 1 mile is 5,280 feet, which is 1,760 yards, which is 63,360 inches. There is no pattern, no logic — just historical accidents hardened into standards.
The metric system spread worldwide during the 19th and 20th centuries. By 2026, only three countries have not officially adopted it: the United States, Myanmar, and Liberia. Even in these countries, metric is the standard for science, medicine, international trade, and military operations.
United States: Uses miles, pounds, gallons, and Fahrenheit for daily life. Metric is used in science, medicine, and the military. Congress passed the Metric Conversion Act in 1975 but made it voluntary — so it never stuck for consumers.
Myanmar: Historically used its own traditional system. Has been gradually adopting metric in recent years, especially in trade and government.
Liberia: Inherited the imperial system from its founding by American colonists. Has been moving toward metric adoption.
The United Kingdom is an interesting middle case — officially metric, but miles remain on road signs, pubs serve pints, and many people express their weight in stone. It is a mixed system in practice.
Use exact conversions for: Engineering and construction, scientific research, medical dosages, legal documents, financial transactions, international shipping, and cooking with baking chemistry (where precision affects outcomes).
Estimates are fine for: Casual conversation, weather checking, fitness tracking, road trip planning, grocery shopping, and rough sizing. If someone asks "how hot is 30 Celsius?" you can say "about 86 Fahrenheit" — nobody needs the fourth decimal place.
For exact conversions, use our unit converter. For mental math in daily life, the shortcuts above will get you within 5 percent every time.
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