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    Pressure Calculator (p = F/A)

    GCSE PhysicsAQAEdexcelOCRGCSE Physics only

    Find pressure, force or area using p = F ÷ A. Enter areas in cm² or mm² and the solver converts to m² properly.

    Quick answer

    Pressure = force ÷ area. Use newtons and square metres to get pascals (Pa). For example, 600 N on 0.020 m² gives 600 ÷ 0.020 = 30,000 Pa. To convert cm² to m², divide by 10,000.

    By Engr. Mehmood Kakar · Updated

    p = F ÷ A
    Find:

    1 m² = 10 000 cm², so divide cm² by 10 000 (not 100).

    Simulation

    Spread the force, cut the pressure

    A block presses on soft ground. Change the force and the contact area: the smaller the area, the bigger the pressure and the deeper it sinks.

    600 N
    300 cm²

    This is why snowshoes stop you sinking and why a drawing pin has a sharp point: same force, very different area.

    Put these numbers in the calculator above

    How to calculate pressure

    Pressure is how concentrated a force is: the force acting at right angles to a surface, divided by the area it acts on:

    pressure = force normal to a surface ÷ area of that surface

    • p is pressure in pascals (Pa); 1 Pa = 1 N/m²
    • F is the force normal (at right angles) to the surface in newtons (N)
    • A is area in square metres (m²)

    A 600 N person standing on 0.020 m² of shoe sole exerts 600 ÷ 0.020 = 30,000 Pa on the floor. The same force on a smaller area gives a bigger pressure, which is why a sharp knife cuts and snowshoes stop you sinking.

    Area conversions are the trap here. A square metre is 100 cm × 100 cm, so 1 m² = 10,000 cm². Divide cm² by 10,000 to get m², not by 100.

    Common mistakes that cost marks

    1. Dividing cm² by 100. 25 cm² is 0.0025 m². Divide by 10,000.
    2. Multiplying instead of dividing. Pressure is force ÷ area. A bigger area means a smaller pressure.
    3. Not converting kPa. 200 kPa is 200,000 Pa.
    4. Using a force that isn’t at right angles. Only the force normal to the surface counts.

    Practice questions

    Try each one on paper first, then reveal the worked answer.

    Q1A person with a weight of 600 N stands on an area of 0.020 m². Calculate the pressure on the floor.[2 marks]
    1. p = F ÷ A
    2. p = 600 ÷ 0.020
    3. p = 30,000 Pa
    Q2A gas exerts a pressure of 200 kPa on a piston of area 0.05 m². Calculate the force on the piston.[3 marks]
    1. Rearrange: F = p × A
    2. Convert: p = 200 × 1000 = 200,000 Pa
    3. F = 200,000 × 0.05
    4. F = 10,000 N
    Q3A force of 50 N acts on an area of 25 cm². Calculate the pressure in Pa.[3 marks]
    1. p = F ÷ A
    2. Convert: A = 25 ÷ 10,000 = 0.0025 m²
    3. p = 50 ÷ 0.0025
    4. p = 20,000 Pa

    Endless practice

    A new question every time, marked instantly. Work it out on paper, then type your answer.

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    Frequently asked questions

    What is the equation for pressure?

    Pressure = force normal to a surface ÷ area of that surface (p = F/A). Pressure is in pascals (Pa), force in newtons (N) and area in square metres (m²).

    What is a pascal?

    One pascal is a pressure of one newton per square metre: 1 Pa = 1 N/m².

    How do I convert cm² to m²?

    Divide by 10,000, because 1 m² = 100 cm × 100 cm = 10,000 cm².

    Why do sharp knives cut better?

    A sharp edge has a tiny area, so the same force produces a much bigger pressure on the food.