kPa to PSI Converter
1 kPa = 0.1450377 psi. Type in either box.
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Dividing by seven, roughly
Kilopascals are the metric world's everyday pressure unit and psi is the American one, so this conversion turns up wherever equipment crosses between them — tyre placards, pressure washers, air compressors, dive gear.
1 kPa = 0.1450377 psi
The number to remember is the other way round: one psi is just under seven kilopascals. So dividing a kilopascal figure by seven gets you close, and 220 kPa ÷ 7 = 31.4 psi against a true 31.9.
One kilopascal is a small pressure. Atmospheric pressure is about 101 kPa, so a reading in the low hundreds is roughly one atmosphere and a reading in the thousands is the kind of pressure found in hydraulics.
The kilopascal
A thousand pascals, and the size that suits everyday pressures. Car tyres run at roughly 200–250 kPa, the atmosphere sits at about 101 kPa, and a domestic water supply is usually somewhere between 200 and 500 kPa.
It is the working unit for pressure through most of the metric world, which is why tyre placards in Europe, Australia and Asia are marked in kPa alongside the bar figure.
Pounds per square inch
PSI is one pound of force spread over one square inch. It is the everyday pressure unit in the United States and still widely used in Britain for tyres, and it is defined exactly, because both the pound-force and the inch are defined exactly.
Almost every psi figure you meet in daily life is gauge pressure — pressure above atmospheric, sometimes written psig. A tyre at 32 psi holds 32 psi more than the air around it, not 32 psi in total.
The working, step by step
Every line updates with whatever you type above. The point is the method, which is the same for any pair of units in this family.
The same quantity, two different numbers
One physical amount, read off two scales. The tick marks do not line up, and the gap between them is the conversion factor made visible.
How much is that?
A number is easier to judge next to something familiar.
Your turn
Reading a method and being able to use it are different things. Answer within half a per cent and it counts as correct.
Score: 0 of 0
How to use this converter
- Type into either box. The other side updates as you go; there is no button to press.
- Swap the direction with the button between the boxes, carrying your value across.
- Set the decimals if the default is more or less precision than you need.
- Copy the answer with its unit, ready to paste.
- Use the shortcut buttons for the values that come up most often.
- Share the result. The address bar tracks what you type, so the link you copy opens on the same number.
Common uses and tips
Where pressure conversions come up
- Tyres. The single most common reason anyone converts pressure. American placards are in psi, European and Asian ones in bar or kPa, and the three appear side by side on the same door sticker.
- Weather. Forecasts use hectopascals or millibars, which are the same size — 1 hPa is 1 mbar. A typical high-pressure system reads about 1020 of either.
- Diving. Cylinder pressures are in bar almost everywhere and psi in the United States. A full 200 bar cylinder is about 2,900 psi.
- Coffee. Espresso machines are specified in bar; nine bar at the group head is the usual target, which is about 130 psi.
- Materials and hydraulics. Tensile strength and hydraulic ratings come in MPa or psi, and the two communities rarely use the same one.
The trap: gauge pressure and absolute pressure
Almost every pressure you read off a dial in daily life is gauge pressure — how much higher than the surrounding air it is. A tyre at 32 psi contains 32 psi more than the atmosphere, so its absolute pressure is about 46.7 psi.
Conversion between units never changes which of the two you have. If you start with a gauge reading you end with a gauge reading. Where it goes wrong is in physics and chemistry, where the gas laws need absolute pressure: add one atmosphere to a gauge figure before it goes into a calculation. The units psig and psia exist precisely to keep the two apart.
Tips worth knowing
- One bar is not one atmosphere. It is 0.9869 of one. The difference is small enough to ignore for a tyre and large enough to matter in a laboratory.
- Millibars and hectopascals are identical. Weather maps use whichever the local service prefers; the number is the same.
- One MPa is about ten atmospheres, which makes megapascals easy to sanity-check against everyday pressures.
- Torr and mmHg are interchangeable in practice, differing by about one part in seven million.
Values people look up most
Each one opens the converter with the number already in it.
- 1 kPa to psi
- 10 kPa to psi
- 50 kPa to psi
- 100 kPa to psi
- 101.325 kPa to psi
- 150 kPa to psi
- 200 kPa to psi
- 210 kPa to psi
- 220 kPa to psi
- 230 kPa to psi
- 240 kPa to psi
- 250 kPa to psi
- 280 kPa to psi
- 300 kPa to psi
- 350 kPa to psi
- 400 kPa to psi
- 500 kPa to psi
- 700 kPa to psi
- 1,000 kPa to psi
Quick reference
| Kilopascals | PSI |
|---|---|
| 1 kPa | 0.145038 psi |
| 10 kPa | 1.450377 psi |
| 50 kPa | 7.251887 psi |
| 100 kPa | 14.503774 psi |
| 101.325 kPa | 14.695949 psi |
| 150 kPa | 21.755661 psi |
| 200 kPa | 29.007548 psi |
| 220 kPa | 31.908302 psi |
| 250 kPa | 36.259434 psi |
| 300 kPa | 43.511321 psi |
| 500 kPa | 72.518869 psi |
| 1,000 kPa | 145.037738 psi |
Questions people ask
What is the formula for kPa to psi?
Multiply by 0.1450377, or divide by 6.894757.
What is 220 kPa in psi?
31.9 psi — the usual pressure for a car tyre.
What is atmospheric pressure in psi?
101.325 kPa is 14.696 psi, usually quoted as 14.7.
Does this convert gauge or absolute pressure?
Whichever you put in. Converting units does not change which kind of pressure you have — a gauge reading converts to a gauge reading. If a calculation needs absolute pressure, add one atmosphere first.