Bearing Life Calculator
Estimate L10 basic rating life for a rolling-element bearing from its dynamic load rating, applied load, and speed.
Enter your values
From the bearing datasheet, plus your operating load and speed.
How this calculator works
Basic rating life in millions of revolutions is calculated as:
C is the bearing's basic dynamic load rating (from its datasheet), P is the equivalent dynamic load actually applied, and p is a life exponent: 3 for ball bearings, 10/3 for roller bearings. Converting to operating hours at a given speed:
N is rotational speed in RPM. L10h is the life, in hours, that 90% of a population of identical bearings would be expected to reach or exceed.
Reading the result
| Application | Typical target L10h |
|---|---|
| Intermittent-use machinery | 4,000 – 8,000 h |
| General industrial machinery | 20,000 – 30,000 h |
| Continuous-duty / critical machinery | 50,000+ h |
Frequently asked questions
What is equivalent dynamic load, P?
P combines radial and axial load components into a single equivalent radial load using factors from the bearing manufacturer's catalog. For pure radial load with no axial component, P simply equals the radial load.
Does this include a reliability adjustment beyond 90%?
No — this gives the standard L10 (90% reliability) life. For higher reliability requirements, manufacturers publish adjustment factors (a1) to apply to this result.