Spring Calculator - Helical Compression

Helical (round wire) Spring calculator, for designing and manufacturing compression springs. To calculate the rate, enter the wire size, diameter and number of coils required to construct the spring. The new improved Helical Compression Spring Calculator allows you to print or email the calculations for later reference.

Spring Calculator - Helical Compression
Physical Sizes
Enter all known physical dimensions, metric or imperial by suffixing with relevant notation, e.g. 12mm 1cm 0.5in etc. (default is inches)
Results (detailed calculations and formula below)
Wire Diameter (d)
Diameter - Outside (Do)
Diameter - Mean (D)
Diameter - Inside (Di)
Free Length (Lo)
Solid Length (Ls)
Total Coils (N)
Active Coils (n)
Rate / Loadings
The rate can be suffixed with kg/mm kg/cm N/mm N/cm lb/in (default)
Spring Rate (S)

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Online Helical (round wire) Spring calculator, for designing and manufacturing compression springs. Free online Engineering calculators

Welcome to this engineering tutorial on the Compression Spring Calculator. Compression springs are widely used in various applications to store and release energy, absorb shock, and maintain force between contacting surfaces. In this tutorial, we will discuss the topic, share interesting facts, explain the formula used in the calculator, provide a real-life example, and explore the factors influencing the performance of compression springs.

1. Compression Springs: Essential Components

Compression springs are mechanical components designed to withstand compressive forces and return to their original length when the applied force is removed. They are typically made of spring steel or other materials with high tensile strength and elasticity. Compression springs find applications in a wide range of industries, including automotive, aerospace, manufacturing, and consumer goods.

Interesting fact: The earliest known use of springs dates back to ancient times, where they were used in mechanisms such as traps and catapults. The development of modern compression springs can be attributed to advancements in materials and manufacturing techniques.

2. The Formula: Calculating Compression Spring Properties

The Compression Spring Calculator uses a formula based on several parameters to calculate the properties of a compression spring. The key formula is:

F = k × Δx


  • F is the applied force or load on the compression spring.
  • k is the spring constant or stiffness of the spring.
  • Δx is the deflection or compression of the spring from its unloaded state.

This formula allows you to calculate the force exerted by a compression spring based on the applied load and the deflection of the spring. The spring constant determines the stiffness of the spring, indicating how much force is required to compress the spring by a given amount.

3. Real-Life Example: Automotive Suspension System

Let's consider a real-life example to understand the practical application of the Compression Spring Calculator. Imagine you are designing a suspension system for a car. The system requires compression springs to absorb shocks and provide a comfortable ride for the passengers.

You have selected a compression spring with a spring constant (k) of 100 N/m and a deflection (Δx) of 50 mm. By using the Compression Spring Calculator and plugging in these values into the formula, you can calculate the force exerted by the spring:

F = 100 × 0.05 = 5 N

Based on the calculation, the compression spring exerts a force of 5 N when compressed with a deflection of 50 mm.

In the automotive suspension system, this information helps engineers determine the appropriate spring stiffness to provide optimal comfort, stability, and handling characteristics for the vehicle.

4. Factors Affecting Compression Spring Performance

Several factors influence the performance of a compression spring. Here are some key factors to consider:

4.1. Material Selection

The choice of material for the compression spring plays a crucial role in its performance. Different materials offer varying levels of strength, durability, and resistance to fatigue. Common materials used for compression springs include high-carbon steel, stainless steel, and various alloys. Engineers need to select the material that best suits the specific application requirements, taking into account factors such as temperature, corrosion resistance, and load-bearing capacity.

4.2. Wire Diameter and Coil Diameter

The wire diameter and coil diameter are important dimensions that impact the behavior of a compression spring. The wire diameter determines the overall strength and load-carrying capacity of the spring, while the coil diameter affects its flexibility and ability to store energy. Finding the right balance between these two dimensions is critical to achieve the desired spring characteristics.

4.3. Spring Rate

The spring rate, often represented by the spring constant (k), measures the stiffness of the compression spring. It indicates how much force is required to compress the spring by a certain amount. The spring rate is determined by the material properties, wire diameter, and coil diameter. Engineers must carefully select the appropriate spring rate to ensure the desired performance of the spring in terms of load capacity and deflection.

4.4. Solid Height and Free Length

The solid height is the length of the compression spring when it is fully compressed and all the coils are touching each other. The free length is the length of the spring when it is in an unloaded state. These dimensions are essential for determining the working range of the spring and ensuring that it operates within its design limits. Engineers must consider factors such as clearance requirements, maximum and minimum deflection, and the potential for coil binding or buckling.

4.5. End Configurations

The end configurations of the compression spring can have a significant impact on its performance. There are various options, including closed and open ends, ground ends, squared ends, or customized configurations. The end configurations affect the stability, alignment, and distribution of forces within the spring. Engineers need to select the appropriate end configuration based on the specific application requirements and the desired behavior of the spring.


The Compression Spring Calculator is a valuable tool for engineers involved in the design and analysis of compression spring applications. By understanding the formula and considering the various factors influencing spring performance, engineers can make informed decisions about material selection, dimensions, and end configurations to meet the specific requirements of their projects.

Compression springs find widespread use in a variety of industries, including automotive, aerospace, machinery, and consumer products. Their ability to store and release energy makes them essential components for absorbing shocks, maintaining forces, and providing functionality in various mechanical systems.

By harnessing the power of the Compression Spring Calculator and applying the principles discussed in this tutorial, engineers can optimize the design and performance of compression springs, ensuring reliable and efficient operation in their respective applications.