Resistor Aging & Tolerance Calculator

14.07.2026

Estimate resistor aging, long-term resistance drift and end-of-life tolerance based on temperature profiles, operating time, electrical load and resistor specifications.

Resistor Aging & Tolerance Calculator

Calculate temperature error, long-term resistance drift, end-of-life tolerance, continuous load and pulse energy from a realistic temperature profile.

Temperature Profile

Preset Profile Self Heating

Self Heating ΔT [°C]

Ambient [°C]	Time [%]

Profile sum -

Resistor & Continuous Load

Nominal Resistance [Ω]

Initial Tolerance [± %]

TCR [± ppm/K]

TCR Reference Temperature [°C]

Continuous Load Input Applied Voltage [V]

Rated Power [W]

Maximum Working Voltage [V]

Field Operation Time [years]

Maximum Film Temperature [°C]

Aging Model

Reference Data

Model: thin-film drift, temperature factor × time exponent

Reference Drift [± %]

Reference Test Time [h]

Reference Film Temperature [°C]

Drift Doubling Interval [K]

Time Exponent n

Aging Direction

Additional Error Contributions

Soldering Shift [± %]

Humidity / Thermal Cycling [± %]

Other Permanent Error [± %]

Voltage Coefficient [± ppm/V]

Results

Predicted Aging Drift-

Equivalent Aging Temperature-

Maximum Film Temperature-

Continuous Power-

Load Ratio-

Permanent EOL Tolerance @ Tref-

Total Operating Tolerance-

End-of-Life Resistance Range-

Tolerance Budget

Contribution	Negative [%]	Positive [%]	Type

Aging Contribution

Ambient [°C]	Film [°C]	Time [%]	Damage Factor	Share [%]

Pulse & Fault Energy

Pulse Type

Pulse / Peak Voltage [V]

Pulse Duration [ms]

Repetition Frequency [Hz]

Datasheet Pulse Capability [J]

Maximum Pulse Voltage [V]

Enter the pulse-energy capability from the selected resistor's datasheet at the applicable pulse duration and temperature. A generic pass/fail value is not valid across resistor technologies.

Peak Power-

Pulse Energy-

Average Pulse Power-

I²t-

Characteristic Time-

Datasheet Rating Check-

Aging Curve

Model Basis

The default thin-film model uses a drift doubling for every 30 K temperature rise and a cube-root dependence on operating time. The film temperature is the ambient profile plus self-heating.

ΔR/R = Drift_ref · 2^{(T − T_ref) / ΔT_2×} · (t / t_ref)ⁿ

For a changing temperature profile, the calculator accumulates the corresponding transformed damage variable. The model is an engineering estimate and must be anchored to the selected resistor's datasheet or qualification data.

Pulse calculations cover square pulses, capacitor discharge and an exponential surge. Repetitive-pulse checking combines average-power usage and pulse-energy usage when a datasheet pulse capability is provided.

References and limits:

Initial tolerance, TCR, long-term drift, humidity, soldering shift and pulse capability are separate specifications. Manufacturer limits, derating curves, maximum element voltage, PCB thermal conditions and qualification tests remain authoritative.