Quick presets
Batch conversion
Conversion history
Formula used
Linear conversions: Metric value = Imperial value × conversion factor Temperature: °C = (°F − 32) × 5 ÷ 9 K = (°F − 32) × 5 ÷ 9 + 273.15 Fuel economy: L/100 km = 235.214583 ÷ US MPG L/100 km = 282.480936 ÷ UK MPG
How to use this calculator
- Select the measurement category.
- Enter a decimal, fraction, or mixed number.
- Choose the source and target units.
- Select precision and number formatting.
- Press Convert or leave live conversion enabled.
- Copy, print, share, or export the completed result.
Common conversion examples
| Imperial value | Metric result | Conversion rule |
|---|---|---|
| 1 inch | 2.54 centimeters | Multiply by 2.54 |
| 1 foot | 0.3048 meters | Multiply by 0.3048 |
| 1 mile | 1.609344 kilometers | Multiply by 1.609344 |
| 1 pound | 0.45359237 kilograms | Multiply by 0.45359237 |
| 1 US gallon | 3.785411784 liters | Multiply by 3.785411784 |
| 1 UK gallon | 4.54609 liters | Multiply by 4.54609 |
| 1 acre | 0.404685642 hectares | Multiply by 0.404685642 |
| 1 PSI | 6.894757293 kPa | Multiply by 6.894757293 |
US and UK Imperial volume differences
A US gallon equals 3.785411784 liters, while a UK Imperial gallon equals 4.54609 liters. The same difference affects pints, quarts, cups, and fluid ounces. Always select the correct system before converting liquid measurements.
Frequently asked questions
Can this calculator convert metric units back to imperial units?
Yes. Select any supported metric unit as the source, then choose a compatible imperial target unit.
Does it accept fractions?
Yes. Inputs such as 1/2, 3/8, and 5 3/8 are parsed automatically.
What is the difference between US and UK gallons?
A UK gallon is larger. The system selector changes relevant liquid unit definitions.
Can negative values be entered?
Negative values are accepted when meaningful, especially for temperature conversions.
How accurate are the results?
Calculations use established conversion factors and retain full internal floating-point precision.
Can I choose the number of decimal places?
Yes. Select between zero and twelve decimal places before converting.
Does batch conversion support fractions?
Yes. Each batch item may be a decimal, fraction, or mixed number.
How does PDF export work?
The Print / Save PDF button opens the browser print dialog, where PDF can be selected.
Is conversion history saved?
Recent results are stored locally in the current browser and can be cleared anytime.
Why are incompatible units blocked?
Units from different physical categories cannot be converted meaningfully without extra information.
What does automatic number format do?
It uses scientific notation only for extremely large or extremely small results.