Engineering calculator · Updated 17 September 2026
Boiler Evaporation Ratio Calculator — Steam-to-Fuel Ratio & Specific Steam
Calculate actual evaporation ratio from steam production and fuel use, then compare against a target and estimate fuel saving at the same steam output.
Inputs
Live results
- Actual evaporation ratio 12.5 kg steam/kg fuel
- Gap to target -3.8461538%
- Fuel required at target 769.23077 kg/h
- Potential fuel difference 30.769231 kg/h
Formula
ER=steam mass/fuel mass.
Worked example
10 t/h steam from 0.8 t/h fuel gives 12.5 kg steam/kg fuel.
Assumptions and limits
- Steam and fuel mass flows must cover the same stable period.
- Fuel quality and steam/feedwater conditions must be comparable for benchmarking.
FAQs
What does this Boiler Evaporation Ratio Calculator calculate?
Calculate actual evaporation ratio from steam production and fuel use, then compare against a target and estimate fuel saving at the same steam output.
Is this suitable for final equipment selection?
Use the result for engineering screening and operating diagnostics. Confirm final selections against measured data, OEM curves and applicable codes.
Why are the assumptions explicit?
Plant results depend on reference conditions, pressure basis, efficiencies and measurement locations. Showing assumptions keeps the calculation auditable.