Physics

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Spring Rate Calculator.

Calculate linear spring rate from force and deflection.

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Results update as you type.

02 / ANSWER

Force

Deflection

Spring rate

0.000000N/m

Results update automatically as you type.

Use Cases

Designing or selecting springs

Determine the stiffness of a spring needed for a specific application by inputting the required force and expected deflection.

Example: If you need a spring to exert 100 N when compressed by 0.05 m, the spring rate is 2000 N/m.

Verifying spring specifications

Check if a spring meets its rated stiffness by measuring the force and deflection and comparing the calculated rate to the spec.

Example: Test a spring with 50 N force and 0.02 m deflection to see if it matches the expected 2500 N/m.

Frequently Asked Questions

What is spring rate?: Spring rate (k) is a measure of a spring's stiffness, defined as the force required to compress or extend the spring by one unit of length. It is calculated by dividing the applied force by the resulting deflection.
How do I use this calculator?: Enter the force applied to the spring in newtons (N) and the deflection (change in length) in meters (m). The calculator will divide force by deflection to give you the spring rate in newtons per meter (N/m).
What units does the calculator use?: The calculator uses newtons (N) for force and meters (m) for deflection. The resulting spring rate is expressed in newtons per meter (N/m).

Tips & Common Mistakes

Tips

Ensure the force is applied along the spring's axis and the deflection is measured from the free length.
Use consistent units: newtons for force and meters for deflection to get the spring rate in N/m.
For linear springs, the rate is constant; for non-linear springs, this calculation gives the average rate over the measured range.
Double-check your measurements: small errors in deflection can significantly affect the calculated rate.

Common Mistakes to Avoid

Using deflection in centimeters or millimeters without converting to meters, which leads to incorrect spring rate values.
Confusing force with mass: ensure you enter the force in newtons, not kilograms (which is mass).
Measuring deflection from the wrong reference point, such as from the compressed length instead of the free length.

Last updated: August 13, 2026

Use Cases

Designing or selecting springs

Determine the stiffness of a spring needed for a specific application by inputting the required force and expected deflection.

Example: If you need a spring to exert 100 N when compressed by 0.05 m, the spring rate is 2000 N/m.

Verifying spring specifications

Check if a spring meets its rated stiffness by measuring the force and deflection and comparing the calculated rate to the spec.

Example: Test a spring with 50 N force and 0.02 m deflection to see if it matches the expected 2500 N/m.

Frequently Asked Questions

What is spring rate?

Spring rate (k) is a measure of a spring's stiffness, defined as the force required to compress or extend the spring by one unit of length. It is calculated by dividing the applied force by the resulting deflection.

How do I use this calculator?

Enter the force applied to the spring in newtons (N) and the deflection (change in length) in meters (m). The calculator will divide force by deflection to give you the spring rate in newtons per meter (N/m).

What units does the calculator use?

The calculator uses newtons (N) for force and meters (m) for deflection. The resulting spring rate is expressed in newtons per meter (N/m).

Tips & Common Mistakes

Tips

Ensure the force is applied along the spring's axis and the deflection is measured from the free length.
Use consistent units: newtons for force and meters for deflection to get the spring rate in N/m.
For linear springs, the rate is constant; for non-linear springs, this calculation gives the average rate over the measured range.
Double-check your measurements: small errors in deflection can significantly affect the calculated rate.

Common Mistakes to Avoid

Using deflection in centimeters or millimeters without converting to meters, which leads to incorrect spring rate values.
Confusing force with mass: ensure you enter the force in newtons, not kilograms (which is mass).
Measuring deflection from the wrong reference point, such as from the compressed length instead of the free length.

Use Cases

Designing or selecting springs

Determine the stiffness of a spring needed for a specific application by inputting the required force and expected deflection.

Example: If you need a spring to exert 100 N when compressed by 0.05 m, the spring rate is 2000 N/m.

Verifying spring specifications

Check if a spring meets its rated stiffness by measuring the force and deflection and comparing the calculated rate to the spec.

Example: Test a spring with 50 N force and 0.02 m deflection to see if it matches the expected 2500 N/m.

Frequently Asked Questions

What is spring rate?

How do I use this calculator?

What units does the calculator use?

The calculator uses newtons (N) for force and meters (m) for deflection. The resulting spring rate is expressed in newtons per meter (N/m).

Tips & Common Mistakes

Tips

Ensure the force is applied along the spring's axis and the deflection is measured from the free length.
Use consistent units: newtons for force and meters for deflection to get the spring rate in N/m.
For linear springs, the rate is constant; for non-linear springs, this calculation gives the average rate over the measured range.
Double-check your measurements: small errors in deflection can significantly affect the calculated rate.

Common Mistakes to Avoid

Using deflection in centimeters or millimeters without converting to meters, which leads to incorrect spring rate values.
Confusing force with mass: ensure you enter the force in newtons, not kilograms (which is mass).
Measuring deflection from the wrong reference point, such as from the compressed length instead of the free length.