The HN Solutions Unit Converter instantly converts length, weight, and temperature between metric and imperial units — from metres to feet, kilograms to pounds, and Celsius to Fahrenheit. Results update in real time as you type, using accurate, internationally accepted conversion factors.
Why our unit converter is better
- Real-time conversion as you type — no submit button.
- The units people actually use across length, weight and temperature.
- Accurate standard conversion factors you can trust.
- Private and fast — it works right in your browser, even offline once loaded.
- Swap units with one click.
How to convert units
- Choose a category: length, weight or temperature.
- Enter a value and pick the units to convert from and to.
- Your converted result appears instantly.
Frequently asked questions
How do I convert metres to feet?
Select Length, enter your value in metres and choose feet as the target unit. One metre equals about 3.28084 feet.
Can it convert temperature?
Yes. It converts between Celsius, Fahrenheit and Kelvin instantly.
Is the unit converter accurate?
Yes. It uses standard, internationally accepted conversion factors.
Is it free to use?
Yes, it is completely free with no sign-up and no limits.
Does it work on mobile?
Yes. It works on any phone, tablet or computer.
Explore more in our free tools hub.
The conversions people get wrong
Temperature is not a simple multiply. Celsius and Fahrenheit have different zero points, so 0°C is 32°F, not 0°F. The formula is ×9/5 then +32. Kelvin shares Celsius’s scale but starts at absolute zero, so it is simply +273.15.
Weight and mass are different quantities. Kilograms measure mass; pounds are commonly used for both. For everyday purposes the conversion is fine, but 1 kg = 2.20462 lb, not 2.2 — and over a large figure that rounding shows.
US and UK gallons are not the same. A US gallon is 3.785 litres, an imperial gallon 4.546. That is a 20% difference, and it catches people out on fuel economy and recipes constantly.
Precision, and when rounding starts to matter
For most everyday conversion, two decimal places is plenty. It stops mattering for cooking and starts mattering fast in three situations:
- Anything cumulative — a rounding error repeated across fifty rows becomes a visible discrepancy.
- Engineering and machining tolerances, where thousandths are the point.
- Medication dosing, where the correct answer is to use a properly calibrated instrument rather than a web tool.
Why 26.2 miles is 42.16 km
The marathon is the conversion most people have seen and never checked. A mile is exactly 1.609344 kilometres by international agreement — that figure is a definition, not a measurement, and has been since 1959.
Multiply and 26.2 miles gives 42.164 km. The official marathon distance is 42.195 km, which is 26.219 miles — so the familiar “26.2” is itself a rounding.
Metric and imperial in the same document
If you write for a mixed audience, give both: “5 km (3.1 miles)”. Put the unit your primary reader thinks in first and the conversion in brackets.
Be consistent about which is primary throughout a single piece. Switching around — distances in miles, weights in kilos, temperatures in Fahrenheit — makes a document tiring to read even when every individual figure is right.
Runs in your browser
Every conversion is calculated on your device, so there is no lag and nothing is transmitted. For percentage work the percentage calculator covers the four patterns, and the BMI calculator handles metric and imperial inputs directly.