Steam Boiler Evaporation Ratio Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 26, 2026Steam Boiler Evaporation Ratio Calculator
One of the oldest boiler performance benchmarks in the industry is also one of the simplest: how many kilograms of steam does a boiler produce per kilogram of fuel burned?
Formula: Ratio = Steam Output / Fuel Input
Example: 5,000 kg/hr of steam from 400 kg/hr of fuel gives an evaporation ratio of 12.5 kg steam per kg fuel.
How to Use This Calculator
- Enter steam output in kg/hr.
- Enter fuel input in kg/hr.
This ratio depends heavily on fuel type, steam pressure, and feedwater temperature, so it is most useful for tracking the same boiler's performance over time rather than comparing across very different boiler designs.