ONE FORMULA, ONE ANSWER
RL Time Constant Calculator
Check the current response time constant of a first-order coil circuit. Choose input units and calculate one value within the stated conditions.
Inputs
Calculations run in this browser. Scientific notation such as 1.2e-3 is supported. Do not group thousands.
Result
RL time constant τ
Enter values and select Calculate.
τ = L / R
Assumptions
Use L,R>0. Include inductor winding resistance in the total resistance. The model is linear and first order, with no saturation or additional poles.
Displayed values are floating-point approximations. Measurement uncertainty and design safety factors are not calculated.
Formula references and credits
NaNa Lab created the code, descriptions, icons and preview images. Text, figures and code from the linked references have not been reproduced.
Physical constants: NIST / CODATA 2022. The values of μ₀ and ε₀ are measured recommendations, not exact defining constants. Values and precision notes are in the source record.
This site includes Google advertising and analytics, and Cloudflare analytics.