Chemistry
Boiling Point Calculator
Find the boiling point of a chosen substance at any external pressure using its own validated Antoine constants.
Your inputs
Change any value to update the result instantly.
Boiling point of water
100.45 °C
In kelvin
373.6 K
External pressure
1,013.25 mbar
Antoine constants used
A = 4.6543, B = 1435.264, C = -64.848
Validated range
-17.2 °C to 99.9 °C
Within range?
No — treat this figure as an extrapolation
There is no single universal boiling-point equation. Each substance uses its own fitted Antoine constants over a stated temperature window; outside that window the answer is an extrapolation.
What this calculator does
Finds the temperature at which a chosen substance boils under a given external pressure, using that substance's own Antoine constants.
What your result means
The boiling temperature for your pressure; lower pressure always means a lower boiling point.
Formula and working
log10(P/bar) = A − B / (C + T); boiling when P_vapour = P_external
- 1
Collect the inputs
Substance = 1; External pressure = 1,013.25 mbar
- 2
Apply the formula
log10(P/bar) = A − B / (C + T); boiling when P_vapour = P_external
- 3
Result
Boiling point of water = 100.45 °C
Frequently asked questions
Symbols and assumptions
- A, B, C
- Antoine coefficients for the substance
- P
- External pressure
- T_b
- Boiling temperature
- • Antoine constants are substance specific and valid only inside their fitted range.
- • The pressure entered is the pressure above the liquid.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Outside the fitted temperature window the result is an extrapolation.
- • Only the listed substances have stored constants; nothing is guessed for others.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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