Fast answers, clean math
Convert length, weight, temperature, volume, area, and speed without waiting through popups or a slow page. Pick a unit, enter a number, and get the result with the formula.
Popular: km to miles, miles to km, cm to inches, kg to lb, C to F, liters to gallons.
Unit converter
Useful reference
| Conversion | Value | Use it for |
|---|---|---|
| 1 kilometer to miles | 0.621371 miles | Running, driving, travel distance |
| 1 meter to feet | 3.28084 feet | Room size, height, project estimates |
| 1 foot to meters | 0.3048 meters | Room size, height, project estimates |
| 1 centimeter to inches | 0.393701 inches | Clothing, product dimensions, crafts |
| 1 inch to centimeters | 2.54 centimeters | DIY, screens, product sizes |
| 1 kilogram to pounds | 2.20462 pounds | Body weight, luggage, shipping |
| 1 pound to kilograms | 0.453592 kilograms | Body weight, baggage, shipping |
| 0°C to Fahrenheit | 32°F | Weather, cooking, thermostat settings |
| 32°F to Celsius | 0°C | Weather, cooking, thermostat settings |
| 1 liter to US gallons | 0.264172 gallons | Fuel, recipes, liquid volume |
| 1 US gallon to liters | 3.78541 liters | Fuel, containers, recipes |
| 100 square meters to square feet | 1076.39 square feet | Apartments, flooring, real estate |
No black box
Most metric conversion formulas use one base unit. Length conversions pass through meters, mass conversions pass through kilograms, and volume conversions pass through liters. Temperature is different because Fahrenheit and Celsius use different zero points.
For example, 5 kilometers to miles is calculated as 5 x 1000 meters, then divided by 1609.344 meters per mile. The answer is 3.10686 miles.
Practical guide
Length and weight conversions on this site use exact reference factors where standards define them. A mile is exactly 1,609.344 meters, an inch is exactly 2.54 centimeters, and a pound is exactly 0.45359237 kilograms. That matters when you are estimating materials, package weights, freight dimensions, or product specifications.
For quick everyday use, a rounded answer is usually easier to read. One kilometer is about 0.62 miles, one kilogram is about 2.2 pounds, and one liter is about 0.26 US gallons. The calculator keeps more precision in the result, while the examples show the rounded numbers most people actually use.
Fahrenheit and Celsius do not share the same zero point, so temperature conversion needs both multiplication and addition or subtraction. Fahrenheit to Celsius subtracts 32 before multiplying by 5/9. Celsius to Fahrenheit multiplies by 9/5 and then adds 32.
Accuracy notes
Most consumer conversions only need two to four decimal places. Construction, recipes, travel, shipping, and fitness estimates rarely benefit from showing every possible digit. Scientific work, manufacturing tolerances, and compliance documents may require the exact factor and a clearly stated rounding rule.
This tool shows the formula so you can see whether the answer came from multiplication, division, or a temperature offset. If you copy a value into a quote, recipe, label, or listing, keep the unit with the number so the meaning is not lost.
| Use case | Good rounding |
|---|---|
| Driving or running distance | 1 or 2 decimal places |
| Body weight or luggage | 1 decimal place |
| Recipes and liquid volume | 2 decimal places or common fractions |
| Product dimensions | Match the precision of the original measurement |
Plain answers
Use a converter that starts from a trusted base unit and shows the formula. That keeps the answer fast while making the math easy to check.
Some conversions create long decimal values. This calculator rounds the displayed result to useful significant digits, while the formulas keep the exact conversion factors.
Yes. The calculator supports common imperial units including inches, feet, miles, ounces, pounds, gallons, and miles per hour.
No. The conversion runs entirely in your browser and the numbers you type are never uploaded. The site does use Google Analytics and advertising, which collect standard usage data described in the privacy policy.
Beyond the calculator
Cups to grams by ingredient, US volume tables, oven temperatures, and the rounding choices that matter in baking.
Estimate km to miles, kg to pounds, and Celsius to Fahrenheit in your head — with the error each shortcut carries.
The 1975 law that made conversion voluntary, what staying half-metric costs, and where America is already metric.
Trust basics
This converter runs in your browser and does not require an account. The measurement values you enter are never uploaded. The site uses Google Analytics and Google AdSense — the privacy policy explains what they collect and how to opt out of personalized ads.