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Reference table

Efficiency Table: Efficiency by Useful output

Reference table of efficiency for Efficiency across a range of useful output values — exact, engine-computed figures you can read off at a glance.

By Vikram Iyer, M.Sc Mathematics · Updated Jun 2026 · 1 min read

This efficiency reference table shows the efficiency for a range of useful output values, assuming a total input of 100. Every figure is computed with the same engine that powers our Efficiency Calculator, so the numbers are exact.

Useful outputEfficiencyEnergy lost
2020.00%80.00
4040.00%60.00
6060.00%40.00
8080.00%20.00
120120.00%-20.00
160160.00%-60.00
240240.00%-140.00
400400.00%-300.00
560560.00%-460.00
800800.00%-700.00

How to use this table

Find the row closest to your useful output and read across to the efficiency. For a value between two rows, the real figure sits between them — or enter your exact numbers in the Efficiency Calculator for a precise answer.

Need a value that is not in the table? — the Efficiency Calculator does it instantly, for free, with the formula and a worked example built in.

Continue exploring science calculators with these tools: Impulse Calculator, Elastic Potential Energy Calculator, Thermal Expansion Calculator, Buoyancy Force Calculator, RPM to Linear Speed Calculator.

Calculators in this guide

Frequently asked questions

Each cell is computed with the standard formula using exact arithmetic — the same calculation behind our Efficiency Calculator — so every figure is accurate for the stated assumptions.

Yes. The table covers common useful output values; for any exact figure, enter your own numbers in the Efficiency Calculator.

Vikram Iyer · M.Sc Mathematics

Vikram Iyer is a mathematics educator with over fifteen years of teaching experience, specialising in making quantitative concepts clear and practical for everyday use.