Bearing Life Calculator

• •Use the Bearing Life Calculator when solving homework or exam problems that require quick numerical verification of your hand calculations — instant feedback helps identify arithmetic errors before they propagate.
• •Use it during the early design phase to rapidly iterate on parameters and narrow down feasible configurations before committing time to detailed finite element simulations or full design packages.
• •Use it when reviewing a colleague's calculation or checking a vendor's data sheet for plausibility — a quick sanity check can prevent costly downstream errors.
• •Use it to generate reference data for a technical report or presentation without manual computation, ensuring consistent, reproducible numbers throughout the document.
• •Use it in the field when a quick estimate is needed and a full engineering software package is not available.

The Bearing Life Calculator is a precision engineering calculation tool designed for students, engineers, and technical professionals. Calculate L10 bearing life in revolutions and hours for ball and roller bearings using basic dynamic load rating All calculations are performed using established engineering formulas from the relevant scientific literature and standards. Inputs support both metric (SI) and imperial unit systems, with unit conversion handled automatically — simply select your preferred unit from the dropdown next to each field. Results are computed instantly in the browser without sending data to a server, ensuring both speed and privacy. This calculator is intended as a supplementary tool for learning and design exploration; always verify results against authoritative references for safety-critical applications.

Rolling element bearings (ball and roller bearings) have a statistical fatigue life expressed as L10 — the life that 90% of bearings will survive under given conditions. The basic equation is L10 = (C/P)^p revolutions, where C is the basic dynamic load rating (from manufacturer's catalog), P is the equivalent load on the bearing, and p = 3 for ball bearings or p = 10/3 for roller bearings. The life in hours is L10h = L10/(60·n), where n is rotational speed in RPM. For bearings under combined radial and axial loads, the equivalent load P = X·F_r + Y·F_a uses factors X and Y from the bearing catalog that depend on the load ratio F_a/F_r and the bearing's contact angle. Life calculations are basic-life; adjusted life factors account for lubrication quality, contamination, reliability requirement (for 95% or 99% reliability instead of 90%), and material. High-quality lubricated clean applications achieve L10 × 2-5× factor over basic life; contaminated or poorly lubricated applications fall below basic life. Typical bearing life targets: industrial machinery 30,000-60,000 hours, automotive 100,000-300,000 km, aerospace 10,000-50,000 hours (with replacement planning), home appliances 5,000-20,000 hours.

• •Electric motor bearing selection: compute required C from expected load and speed, then select a bearing with adequate rating. Motor bearings are usually specified for 20,000-40,000 hours of L10 life.
• •Pump and fan bearings: select bearings for the expected service life (typically 20,000-40,000 hours for commercial applications) at the operating load.
• •Gearbox and transmission bearings: support gear reactions under varying load patterns; use equivalent load calculations to account for duty cycle variation.
• •Wheel hub bearings: automotive wheel bearings see combined radial and axial loads that vary with turning and braking. Design targets are 100,000-300,000 km of vehicle life.
• •Wind turbine main bearings: critical components with expected lives of 20-30 years. Oversizing provides margin for the difficulty of replacement at operational wind turbines.