Bearing Life Calculator | L10 Life, Load, Speed

📖 How to Use This Bearing Life Calculator

Enter dynamic load rating (C) – Found in bearing catalogs (kN). This is the constant load under which a bearing will last 1 million revolutions.

Enter equivalent load (P) – The actual load on the bearing, considering radial and axial forces (kN).

Set rotational speed (n) – Operating speed in revolutions per minute (RPM).

Choose life exponent (p) – 3 for ball bearings, 10/3 (≈3.33) for roller bearings. You can adjust as needed.

Use presets or custom – Click presets for typical configurations or enter your own values.

⚙️ What is L10 Bearing Life?

L10 life is the number of revolutions (or hours at a given speed) that 90% of a group of identical bearings will achieve before the first signs of fatigue appear. It's the standard measure for bearing rating life, defined in ISO 281 and ANSI/ABMA standards.

The basic formula is:

L₁₀ (hours) = (C / P)ᵖ × 10⁶ / (60 × n)
where C = dynamic load rating, P = equivalent dynamic load, p = life exponent (3 for ball, 10/3 for roller), n = speed in RPM.

💡 Practical Applications

Industrial gearboxes – Ensure bearing life matches maintenance intervals.
Electric motors – Critical for pump, fan, and compressor applications.
Automotive – Wheel bearings, transmission bearings.
Agricultural machinery – Tractor PTO, harvester bearings.
Conveyor systems – Roller bearings in material handling.

❓ Frequently Asked Questions (FAQ)

What does L10 mean?

L10 is the life at which 90% of bearings in a population are expected to survive. It's the most common rating life used in industry.

What is the difference between ball and roller bearing exponents?

Ball bearings have a life exponent p = 3. Roller bearings (cylindrical, tapered, spherical) have p = 10/3 ≈ 3.33. This reflects different fatigue mechanisms.

How do I find the dynamic load rating (C) for my bearing?

The C value is provided in bearing manufacturer catalogs or datasheets (e.g., SKF, NSK, Timken). It's a key parameter for life calculations.

What if the equivalent load (P) varies over time?

For variable loads, use the equivalent dynamic load (P) calculated from the load spectrum. Our calculator assumes a constant equivalent load.

What is a good bearing life for my application?

It depends on the application. Typical targets: 10,000–30,000 hours for general machinery, 50,000+ hours for critical equipment. Always consult design guidelines.

Can I use this calculator for sealed bearings?

Yes, the L10 life formula applies to all rolling bearings. However, sealed bearings may have additional life considerations (lubrication, contamination).