Bearing Load Rating Calculator

Work out bearing load rating instantly with clear inputs, formula shown and shareable results.

About Bearing Load Rating Calculator

A bearing catalogue quotes life against a single equivalent load, so combined radial and axial loading must be reduced to P = X Fr + Y Fa using factors from the bearing type and the axial-to-radial ratio. When the axial component is small the plain radial load governs, which is why the larger of the two values is taken.

Formula

Equivalent dynamic load

P = max(Fr, X x Fr + Y x Fa)

Fr: Radial load
Fa: Axial load
X: Radial factor
Y: Axial factor

Worked example

With the default values below, Bearing Load Rating Calculator returns Equivalent dynamic load of 1,272.0. Change any input above and every figure here is recalculated in your browser.

Inputs used

Radial loadminimum 0 lbf: 1,200 lbf
Axial loadminimum 0 lbf: 400 lbf
Radial factor Xminimum 0.1: 0.56
Axial factor Yminimum 0.1: 1.5

Results

Equivalent dynamic load: 1,272.0 lbf
Radial contribution: 672.0 lbf
Axial contribution: 600.0 lbf
Axial to radial ratio: 0.333

Step by step

1Values used
2Equivalent dynamic load
3Equivalent dynamic load= 1,272.0 lbf
4Radial contribution= 672.0 lbf
5Axial contribution= 600.0 lbf
6Axial to radial ratio= 0.333

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Preliminary estimate only. Confirm load factors, limiting speed and lubrication against the bearing manufacturer's catalogue.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Preliminary estimate only. Confirm load factors, limiting speed and lubrication against the bearing manufacturer's catalogue.

Frequently Asked Questions

How is the Bearing Load Rating figure worked out?

P = max(Fr, X x Fr + Y x Fa). A bearing catalogue quotes life against a single equivalent load, so combined radial and axial loading must be reduced to P = X Fr + Y Fa using factors from the bearing type and the axial-to-radial ratio.

Where do X and Y come from?

From the manufacturer's tables for the bearing series, indexed by the axial-to-radial ratio against a limiting value e. A deep groove ball bearing commonly uses X = 0.56 with Y between 1.0 and 2.3.

What values do I need to enter?

This calculator takes 4 inputs: Radial load, Axial load, Radial factor X, Axial factor Y. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.