Metric to Imperial Calculator

Q: What is the difference between a metric ton, a US ton, and a UK ton?

They are three different weights with similar names: Metric ton (tonne): 1,000 kg = 2,204.623 lb 1 US short ton: 2,000 lb = 907.18474 kg 1 UK long ton: 2,240 lb = 1,016.047 kg 2 The long ton is the heaviest and the short ton is the lightest.

Q: How many square feet are in an acre and in a hectare?

One acre is 43,560 square feet. 1 That is about 4,046.86 square meters. One hectare is 10,000 square meters. 1 That is about 107,639 square feet, or about 2.47 acres. An American football field, end zones included, is 360 feet long and 160 feet wide. 6 A hectare is about 1.9 of those fields.

Introduction

This Metric to Imperial Calculator changes metric units into imperial units in one step. Type a number, pick your units, and the answer shows up right away. You can also go the other way and turn imperial units back into metric.

The tool covers five groups of measurements:

Length: meters to feet, centimeters to inches, kilometers to miles, and more
Area: square meters to square feet, hectares to acres
Volume: liters to gallons, milliliters to fluid ounces (US and UK)
Weight / Mass: kilograms to pounds, grams to ounces, tonnes to tons
Temperature: Celsius to Fahrenheit, Kelvin, and Rankine

Every answer comes with a step-by-step solution, so you can see the math and learn the conversion factor. A table shows your value in every unit, and a chart compares them side by side. You can pick how many decimal places you want, swap the two sides with one click, and copy the result with the copy button.

How to use our Metric to Imperial Calculator

Pick a measurement type, type a value in the metric or imperial box, and the tool shows the converted value, the step-by-step math, a full unit table, and a comparison chart.

Measurement tab: Choose Length, Area, Volume, Weight/Mass, or Temperature at the top. Each tab has its own units and its own result.

Metric value: Type the number you want to convert, like 10 for 10 meters. Use 0 or more for all types except temperature, which allows negatives.

Metric unit: Pick the metric unit that matches your number, such as millimeters, meters, kilometers, liters, grams, or Celsius.

Imperial value: Leave this blank to convert metric to imperial. Or type a number here to convert imperial to metric instead. The tool fills the other box for you.

Imperial unit: Pick the imperial unit you want, such as inches, feet, miles, gallons, pounds, or Fahrenheit.

Swap button: Click Swap to flip the direction of the conversion between metric and imperial.

Result precision: Choose how many decimal places the answer shows: 2, 4, 6, or full 9-decimal precision.

Copy button: Click the copy icon next to either box to copy that value to your clipboard.

Calculate and Reset: Results update as you type, but you can click Calculate to refresh them. Click Reset to clear the tab and start over.

Metric to Imperial Conversion

The world uses two main measuring systems. The metric system uses meters, liters, grams, and degrees Celsius. Most countries use it. The imperial system uses inches, feet, miles, gallons, pounds, and degrees Fahrenheit. The United States uses it most often, and the United Kingdom still uses parts of it.

Converting from metric to imperial means changing a number from one system to the other without changing the real size. A 5 kilometer race is still the same distance if you call it 3.11 miles. You just multiply by a fixed number called a conversion factor.

Common Metric to Imperial Conversions

Length: 1 centimeter = 0.3937 inches; 1 meter = 3.28084 feet; 1 kilometer = 0.621 miles¹
Area: 1 square meter = 10.76391 square feet; 1 hectare = 2.471 acres¹
Volume: 1 liter = 0.2641721 US gallons; 1 liter = 33.81402 US fluid ounces¹
Weight: 1 gram = 0.03527396 ounces; 1 kilogram = 2.204623 pounds; 1 metric ton = 1.102311 short tons¹
Temperature: °F = (°C × 9/5) + 32²

Why Length, Area, and Volume Are Different

Area and volume factors are not the same as length factors. Area uses the length factor squared, and volume uses it cubed. One foot is 0.3048 meters, but one square foot is 0.3048 × 0.3048 = 0.0929 square meters. That is why 1 square meter equals about 10.76 square feet, not 3.28.

Watch Out for US and UK Gallons

US and UK liquid units share the same names but hold different amounts. A US gallon is 3.785 liters.¹ A UK (imperial) gallon is 4.546 liters, about 20% bigger.¹ Pints and fluid ounces differ too. Always check which one a recipe or fuel figure means.

Temperature Works by Formula

Temperature is different. You cannot just multiply, because the scales start at different points. Celsius freezes water at 0°, Fahrenheit at 32°. So you multiply and then add or subtract. Kelvin and Rankine are absolute scales that start at absolute zero, the coldest point possible.

Quick Mental Tricks

Kilometers to miles: multiply by 0.6 (5 km ≈ 3 mi)
Kilograms to pounds: double it and add 10% (10 kg ≈ 22 lb)
Meters to feet: multiply by 3 and add a bit (10 m ≈ 33 ft)
Celsius to Fahrenheit: double it and add 30 (20°C ≈ 70°F)

These tricks are close enough for everyday use. For school work, building, shipping, or medicine, use the exact factors instead.

Formulas used

General unit conversion (ratio method)

V_{to} = V_{from} \times \frac{f_{from}}{f_{to}}

Step 1: Convert input to base unit

V_{base} = V_{from} \times f_{from}

Step 2: Convert base unit to target unit

V_{to} = \frac{V_{base}}{f_{to}}

Reverse conversion factor

1\,\text{unit}_{to} = \frac{f_{to}}{f_{from}}\,\text{unit}_{from}

Temperature to Kelvin (base scale)

K = T_{^\circ C} + 273.15 \quad;\quad K = (T_{^\circ F} + 459.67) \times \frac{5}{9} \quad;\quad K = T_{^\circ R} \times \frac{5}{9}

Kelvin to target temperature scale

T_{^\circ C} = K - 273.15 \quad;\quad T_{^\circ F} = K \times \frac{9}{5} - 459.67 \quad;\quad T_{^\circ R} = K \times \frac{9}{5}

Direct Celsius to Fahrenheit ²

T_{^\circ F} = \left(T_{^\circ C} \times \frac{9}{5}\right) + 32

Direct Fahrenheit to Celsius ²

T_{^\circ C} = (T_{^\circ F} - 32) \times \frac{5}{9}

Frequently asked questions

How do I change my height from centimeters to feet and inches?

Divide the centimeters by 2.54 to get total inches. Then divide the inches by 12. The whole number is your feet, and what is left over is your extra inches.

Example: 170 cm ÷ 2.54 = 66.93 in. 66.93 ÷ 12 = 5 with 6.93 left. So 170 cm is about 5 ft 7 in.

What temperature is the same in Celsius and Fahrenheit?

Minus 40. At that point the two scales meet, so −40 °C equals −40 °F. It is the only temperature where both numbers match.

Why is 1 inch exactly 2.54 centimeters?

It was agreed on. In 1959 the national standards laboratories of the United States, the United Kingdom and other countries agreed on an international yard and pound.³ They fixed the yard at exactly 0.9144 meters and the pound at exactly 0.45359237 kg.³ That makes the inch exactly 2.54 cm.¹

Because these are definitions, not measurements, there is no rounding error in them.

Which countries still use the imperial system?

The United States uses it for everyday life. Liberia and Myanmar also still use non-metric units in many places.

The United Kingdom is mixed. Road signs use miles and pubs sell pints, but food is sold in grams and liters.

What is the difference between a metric ton, a US ton, and a UK ton?

They are three different weights with similar names:

Metric ton (tonne): 1,000 kg = 2,204.623 lb¹
US short ton: 2,000 lb = 907.18474 kg¹
UK long ton: 2,240 lb = 1,016.047 kg²

The long ton is the heaviest and the short ton is the lightest.

How many square feet are in an acre and in a hectare?

One acre is 43,560 square feet.¹ That is about 4,046.86 square meters.

One hectare is 10,000 square meters.¹ That is about 107,639 square feet, or about 2.47 acres. An American football field, end zones included, is 360 feet long and 160 feet wide.⁶ A hectare is about 1.9 of those fields.

Is a fluid ounce a measure of weight or volume?

A fluid ounce measures volume, which is how much space a liquid fills. A plain ounce measures weight.

They are close for water. One US fluid ounce of water weighs about 1.04 ounces. But for oil, honey, or flour the two numbers are very different, so never swap them in a recipe.

How do I convert kilograms into stones and pounds?

Multiply the kilograms by 2.2046 to get pounds. Then divide the pounds by 14.¹ The whole number is stones and the rest is pounds.

Example: 70 kg × 2.2046 = 154.3 lb. 154.3 ÷ 14 = 11 with 0.3 left. So 70 kg is 11 st 0.3 lb.

What is 180°C in Fahrenheit for baking?

180 °C is 356 °F, and most recipes round it to 350 °F. Other common oven settings:

160 °C = 320 °F (set 325 °F)
200 °C = 392 °F (set 400 °F)
220 °C = 428 °F (set 425 °F)

Why is a nautical mile longer than a normal mile?

A nautical mile is based on the Earth, not on feet. It comes from one minute of latitude.⁴ It is set at exactly 1,852 meters.¹

A normal (statute) mile is 1,609.344 meters.¹ So one nautical mile is about 1.15 regular miles. Ships and planes use nautical miles because they match map lines.⁴

How fast is 100 km/h in miles per hour?

100 km/h is 62.14 mph. To convert any speed, multiply kilometers per hour by 0.6214. To go back, multiply mph by 1.609344.²

Quick check: 50 km/h ≈ 31 mph, 80 km/h ≈ 50 mph, 120 km/h ≈ 75 mph.

Is a meter longer than a yard?

Yes. One meter is 1.0936 yards, so it is about 3.37 inches longer than a yard. One yard is 0.9144 meters exactly.¹

Why do I get a slightly different number when I convert back?

Rounding. If you turn 1 meter into 3.28 feet and then turn 3.28 feet back into meters, you get 0.99974 m instead of 1 m.

Keep more decimal places during the math and round only at the end. That keeps the small error from growing.

How many milliliters are in a cup?

It depends on the cup. A US customary cup is 8 US fluid ounces.² That is 236.59 mL. US food labels use a rounded 240 mL cup.⁵ A metric cup, used in Australia and New Zealand, is 250 mL.

For baking, the small gap rarely matters. For medicine, use the exact number.

Sources

NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement. National Institute of Standards and Technology. 2026;Units, pp. C-5 to C-8; conversion tables, pp. C-9 to C-17; Tables of Equivalents, pp. C-21 to C-27. Accessed September 29, 2026.

Butcher KS, Crown LD, Gentry EJ. The International System of Units (SI) - Conversion Factors for General Use (NIST Special Publication 1038). National Institute of Standards and Technology. 2006;Sections 5.1.7 Velocity and 5.2.1 Mass; footnotes 19 (cup) and 33 (temperature), pp. 10-13. Accessed September 29, 2026.

Refinement of Values for the Yard and the Pound. National Bureau of Standards. 1959;Federal Register, Vol. 24, No. 128, p. 5348. Accessed September 29, 2026.

What is the difference between a nautical mile and a knot? National Ocean Service, National Oceanic and Atmospheric Administration. Accessed September 29, 2026.

21 CFR 101.9 Nutrition labeling of food. U.S. Food and Drug Administration (Electronic Code of Federal Regulations). § 101.9(b)(5)(viii). Accessed September 29, 2026.

2026 Official Playing Rules of the National Football League. National Football League. 2026;Rule 1, Section 1, Article 1. Accessed October 7, 2026.

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