Free online calculator

Unit Converter

Convert common metric, Imperial, and US measurements instantly across nine useful categories.

Reviewed 18 August 2026 · Runs privately in your browser

Calculate your result

Results update instantly and all calculations stay in your browser.

How unit conversion works

Each category has one base unit. Linear measurements convert to that base with a declared factor, then from the base to the destination. Temperature uses explicit functions for different zero points.

Stable identifiers and URL slugs keep definitions reusable for future focused conversion pages without duplicating formulas.

Worked example

1 kilometre is approximately 0.621371 miles, 1 kilogram is approximately 2.204623 pounds, and 1 bar is approximately 14.503774 psi.

Frequently asked questions

Which categories are supported?

Version 1 includes length, mass, temperature, area, volume, speed, pressure, energy, and power.

How accurate are conversions?

The engine uses declared standard factors and retains more precision internally than it displays.

Why does temperature use different formulas?

Celsius, Fahrenheit, and Kelvin have different zero points, requiring offset functions.

Are US and Imperial volume units the same?

No. For example, US and Imperial gallons have different volumes.

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