About the Efficiency Calculator
Efficiency as output ÷ input × 100 — for machines, energy conversion, processes or work.
Also known as: efficiency formula, machine efficiency, energy efficiency percentage, output over input, machine-efficiency.
How to use this calculator
- Enter useful output, total input.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Open “Step-by-step” to see how the answer was worked out.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
Efficiency = Useful output ÷ Total input × 100
Worked example
Using the values pre-filled in the calculator above:
- Useful output = 750
- Total input = 1,000
the calculator returns:
- Efficiency: 75%
- Losses: 250
Working
Efficiency = 750 ÷ 1,000 × 100 = 75%