Pressure Calculator
Pressure from a force spread over an area, in pascals, bar, psi and atmospheres.
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Your details
Result
- Pressure
- 2,000 Pa
- In kilopascals
- 2 kPa
- In bar
- 0.02 bar
- In psi
- 0.29008 psi
- In atmospheres
- 0.019738 atm
One pascal is one newton per square metre
Standard atmospheric pressure is 101,325 Pa
1000 N spread over 0.5 m²…
P = F ÷ A
1000 ÷ 0.5
P = 2,000 Pa
Formula — written step by step
1000 newtons over half a square metre…
P = F ÷ A
1000 ÷ 0.5
P = 2000 Pa
P is pressure in pascals, F the force in newtons and A the area it is spread over. One pascal is one newton per square metre — a very small pressure, which is why kilopascals and bar are used in practice.
A worked example
Why stiletto heels damage floors
- Person
- 60 kg — 588 N
- Flat shoe
- 150 cm² per foot
- Stiletto heel
- 1 cm²
- Flat shoe: 588 ÷ 0.015 = 39,200 Pa
- Stiletto: full weight on one heel
- 588 ÷ 0.0001
- = 5,880,000 Pa
About 5.9 MPa — 150 times the pressure
The force is identical in both cases; only the area changes. This is why a stiletto can dent hardwood that takes an elephant’s footfall without marking — the elephant weighs far more but spreads it over a vastly greater area.
How to use this calculator
- Enter the force in newtons. To get the force from a mass, multiply by 9.81 or use the force calculator.
- Enter the area and pick its unit.
- Read the result in whichever unit suits: pascals for physics, kPa or bar for engineering, psi for tyres and plumbing in the United States.
- Remember the atmosphere is already pressing at 101,325 Pa — most gauges read the excess above that, not the absolute value.
Force spread over an area
Pressure is force divided by the area it acts on. The same force concentrated into a smaller area produces a far higher pressure, which is the principle behind every blade, needle and nail ever made.
The SI unit is the pascal, one newton per square metre. It is a small unit — atmospheric pressure is about 101,000 of them — so kilopascals, bar and psi are more common in practice.
Gauge pressure against absolute
Most pressure gauges read zero in open air, because they measure the difference from atmospheric rather than from a vacuum. That is gauge pressure, and it is what tyre and boiler readings mean.
Absolute pressure adds the atmosphere back on. A tyre inflated to 32 psi gauge holds about 46.7 psi absolute. Which one is meant matters whenever the ideal gas law is involved, since that law requires absolute pressure — using a gauge reading there produces a badly wrong answer.
Pressure in fluids
In a fluid, pressure rises with depth as the weight of everything above accumulates: about 9,810 pascals for every metre of fresh water, so roughly one atmosphere every ten metres.
Fluid pressure acts equally in all directions at a given depth, which is what makes hydraulics possible. Pascal’s principle says pressure applied to a confined fluid transmits undiminished throughout, so a small force on a small piston becomes a large force on a large one — the same pressure, a greater area.
Formula & methodology
What this calculator assumes
- Assumes the force is spread evenly over the area. A concentrated load produces far higher local pressure than the average.
- Results are absolute pressure. Most gauges read gauge pressure, which is this minus one atmosphere.
- The standard atmosphere is defined as exactly 101,325 Pa, and psi as exactly 6,894.757293168361 Pa.
Sources
Pressure units and reference points
| Pressure | In pascals | In bar | In psi |
|---|---|---|---|
| Standard atmosphere | 101,325 | 1.013 | 14.70 |
| Car tyre (typical) | 220,000 | 2.20 | 32 |
| Bicycle tyre (road) | 690,000 | 6.90 | 100 |
| Espresso machine | 900,000 | 9.00 | 130 |
| 10 m under water | ~200,000 | 2.00 | 29 |
Every 10 metres of water depth adds roughly one atmosphere. Tyre pressures are almost always quoted as gauge pressure — the amount above atmospheric — so a "32 psi" tyre is at about 46.7 psi absolute.
Frequently asked questions
How do I convert a weight in kilograms to a force?
Multiply by 9.81 to get newtons. A 60 kg person exerts about 588 N.
What is the difference between gauge and absolute pressure?
Gauge pressure is measured relative to the atmosphere and reads zero in open air. Absolute pressure is measured from a vacuum and is about 101,325 Pa higher.
Why is a pascal so small?
It is one newton — roughly the weight of an apple — spread over a whole square metre. Everyday pressures involve much larger forces or much smaller areas.
Which unit should I use?
Pascals and kilopascals for physics and engineering, bar in much of Europe, psi in the United States and for tyres. All are shown so no conversion is needed.