Newton's Law of Cooling Calculator
Enter the initial temperature, ambient temperature, and cooling constant to get the temperature at any time plus a step-by-step table.
Parameters
Same unit as T₀ above.
Units: 1/time. Must be > 0.
Number of equally-spaced steps from 0 to t.
Result at t
T₀
—
Tamb
—
Time t
—
T(t)
—
T(t) = T_amb + (T₀ − T_amb) · e^(−k·t)
Time constant τ = 1/k
—
Half-gap time t½
—
Temperature drop ΔT
—
% of gap remaining
—
Temperature vs. Time Table
| Time | Temperature | Gap to Tamb | % Cooled |
|---|
Set parameters and click Calculate to see results.
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Summary
Enter the initial temperature, ambient temperature, and cooling constant to get the temperature at any time plus a step-by-step table.
How it works
- Enter the initial object temperature T₀.
- Enter the ambient (surrounding) temperature T_amb.
- Enter the cooling constant k (per minute or per second, matching your time unit).
- Enter the target time t to evaluate.
- The calculator applies T(t) = T_amb + (T₀ − T_amb)·e^(−kt) and shows the result.
- A table lists temperatures at regular intervals from 0 to your target time.
Use cases
- Estimate how long a hot drink takes to reach a drinkable temperature.
- Predict the body temperature drop at a crime scene for forensic analysis.
- Model food cooling rates to meet food-safety guidelines.
- Verify experimental heat-transfer data against theory.
- Determine the time constant of a thermal system in engineering.
- Teach or study exponential decay in physics and calculus courses.
Frequently Asked Questions
Last updated: 2026-06-11 ·
Reviewed by Nham Vu