Compute pressure, force, or area — P = F / A
Powered by Toolraxy · Physics & engineering calculator
Founder & CEO, Toolraxy
Faiq Ur Rahman is a web designer, digital product developer, and founder of Toolraxy, a growing platform of web-based calculators and utility tools. He specializes in building structured, user-friendly tools focused on health, finance, productivity, and everyday problem-solving.
User Ratings:
ADVERTISEMENT
ADVERTISEMENT
Pressure is force spread over area, it’s the reason a sharp knife cuts easily while a dull one struggles, why hydraulic systems can lift heavy loads, and why your car’s tires need the right amount of air. Whether you’re a mechanic checking tire pressures, an engineer designing hydraulic systems, or a physics student learning about pressure, understanding the relationship between force, area, and pressure is fundamental.
This PSI calculator lets you compute pressure, force, or area using the simple formula P = F/A. Choose the variable you need, enter the other two, and the tool handles the rest including automatic unit conversions for force (lbf, N, kN), area (in², ft², m², cm², mm²), and pressure (psi, kPa, bar, atm). Whether you’re analyzing a pneumatic system, sizing a hydraulic cylinder, or simply converting between pressure units, this calculator delivers instant, accurate results. All calculations run locally in your browser, keeping your data private.
Choose what you want to calculate — Pressure (PSI), Force, or Area — using the mode buttons at the top.
For Pressure mode: enter the Force and the Area over which the force is applied.
For Force mode: enter the Pressure and the Area to find the total force.
For Area mode: enter the Force and the Pressure to find the required area.
Select the appropriate units for each input from the dropdown menus.
Review the calculated result, along with pressure conversions to kPa, bar, and atm.
The calculator applies the fundamental relationship between pressure, force, and area. Depending on which variable you’re solving for, the tool uses one of three formula variations.
Formula: P = F / A (Pressure = Force ÷ Area)
Derived Formula: F = P × A (Force = Pressure × Area)
Derived Formula: A = F / P (Area = Force ÷ Pressure)
All inputs are converted to SI base units before computation: force to newtons, area to square meters, and pressure to pascals. Results are then displayed in multiple unit systems — pressure in psi, kPa, bar, and atm; force in lbf and N; area in in², ft², and m².
The calculator supports a wide range of units:
Force: pound-force (lbf), newtons (N), kilonewtons (kN)
Area: square inches (in²), square feet (ft²), square meters (m²), square centimeters (cm²), square millimeters (mm²)
Pressure: PSI, kPa, bar, atmosphere (atm)
A hydraulic press applies a force of 100 lbf over a piston area of 10 in². What pressure does the system produce?
Step 1: Identify the known values
Force (F) = 100 lbf
Area (A) = 10 in²
Step 2: Apply the formula
P = F / A = 100 / 10 = 10 PSI
Step 3: Convert to other units (optional)
10 PSI = 68.95 kPa
10 PSI = 0.689 bar
10 PSI = 0.680 atm
Interpretation: The hydraulic press produces a pressure of 10 PSI. If you needed to find the force instead, you would multiply pressure by area. If you needed the area, you would divide force by pressure.
PSI stands for Pounds per Square Inch. It’s a unit of pressure that measures the force in pounds applied to one square inch of area. One PSI equals 1 lbf/in².
To convert PSI to kPa, multiply by 6.89476. For example, 10 PSI × 6.89476 = 68.95 kPa. The calculator displays both values for you.
The formula for PSI is P = F/A, where P is pressure in PSI, F is force in pounds-force, and A is area in square inches. If you’re using other units, you’ll need to convert to PSI separately.
PSI is a general term for pressure. PSIG stands for Pounds per Square Inch Gauge, it measures pressure relative to atmospheric pressure. PSIA (absolute) measures pressure relative to a perfect vacuum. At sea level, atmospheric pressure is about 14.7 PSI, so PSIA = PSIG + 14.7.
1 PSI = 6,894.76 pascals (Pa). Since 1 kPa = 1,000 Pa, 1 PSI ≈ 6.895 kPa. The calculator handles these conversions automatically.
1 bar = 14.5038 PSI. Conversely, 1 PSI = 0.06895 bar. The calculator displays pressure in both units.
Yes, the calculator is ideal for hydraulic and pneumatic system calculations. It helps determine the pressure needed for a given force and piston area, or the force produced by a given pressure and area.
For direct PSI calculation, force should be in pounds-force (lbf). The calculator supports multiple force units and converts them automatically to the correct units for the calculation.
ADVERTISEMENT
ADVERTISEMENT
