Two-Point Calibration Calculator

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Point 1 — raw reading

Point 1 — true value e.g. °C in ice

Point 2 — raw reading

Point 2 — true value e.g. °C in the room

A raw reading to convert

Uncertainty in each true value ± in your units

Enter two known points and a raw reading, then press Calculate.

From the book — Chapter 6. slope = (out₂ − out₁) ÷ (in₂ − in₁); offset = out₁ − slope × in₁. Calibrate across the range you care about, not the range that is convenient.

Chapter 6's method, including why a wrong span is worse than no span. Everything stays in your browser — no sign-up, nothing stored.