Unit converter
Convert 14 quantities, from inches and pounds to bar, inH₂O and l/min. Results appear as you type, and the numbers stay in your browser.
1 in = 2.54 cm1 cm = 0.3937007874 in
| Unit | Value |
|---|---|
| 25,400 | |
| 25.4 | |
| 2.54 | |
| 0.254 | |
| 0.0254 | |
| 0.0000254 | |
| 1 | |
| 0.08333333333 | |
| 0.02777777778 | |
| 0.00001578282828 | |
| 0.00001371490281 |
How to use the converter
- Pick a quantity, such as Pressure or Flow rate.
- Type a value. A decimal point or comma both work, and very large or small numbers can be written as
1.5e-6. - Choose the units to convert from and to. The result and the table update as you type.
- Click any unit in the table to make it the target unit.
Copy link saves your settings in the page address, so you can send someone a ready conversion or bookmark it.
How it calculates
Every value is first converted to the SI base unit (metre, kilogram, pascal and so on), then to the target unit. The factors come from exact definitions, so rounding errors don't pile up:
- inch = 0.0254 m and foot = 0.3048 m,
- pound = 0.45359237 kg,
- standard gravity g₀ = 9.80665 m/s², which defines psi, kgf/cm² and inches of water,
- US gallon = 231 cubic inches = 3.785411784 L,
- mechanical horsepower = 550 ft·lbf/s ≈ 745.7 W.
Temperature scales have different zero points, so instead of a factor the converter shows the formula, such as °F = °C × 9/5 + 32. Results are rounded to the number of significant digits you choose, 10 by default.
Common conversions
| Conversion | Result |
|---|---|
| 1 bar → psi | 14.50377 psi |
| 1 psi → kPa | 6.894757 kPa |
| 1 kW → hp | 1.341022 hp |
| 1 in → cm | 2.54 cm |
| 1 lb → kg | 0.4535924 kg |
| 1 gpm (US) → l/min | 3.785412 l/min |
| 100 °C → °F | 212 °F |
| 1 GB → GiB | 0.9313226 GiB |
| 1 inH₂O → Pa | 249.0889 Pa |
| 1 N·m → lbf·ft | 0.7375621 lbf·ft |
Common questions
How many psi is 1 bar?
1 bar is about 14.5038 psi. The other way round, 1 psi is about 0.0689 bar, or 6.895 kPa.
What is the difference between hp and PS?
Mechanical horsepower (hp) is 745.7 W. Metric horsepower (PS, or KM in Polish) is 735.5 W. The difference is about 1.4%, so 100 PS is about 98.6 hp.
What is the difference between MB and MiB?
A megabyte (MB) is 1,000,000 bytes and a mebibyte (MiB) is 1,048,576 bytes, or 2²⁰. Drive makers state capacity in GB while operating systems often show GiB, which is why a 1 TB drive appears as about 931 GiB.
What is inches of water (inH₂O)?
It is the pressure of a 1-inch column of water, conventionally 249.08891 Pa. It is used for low pressures and pressure differences, for example in HVAC, filters and differential pressure transmitters.
Is anything I type sent to a server?
No. The converter runs entirely in your browser and never sends the values you enter anywhere.