Compressed Air Leak Cost Calculator
The air lost through a leak of a given size at your line pressure, and what it costs in compressor electricity over a year — the number that justifies a leak survey.
Air escapes a hole at sonic speed, so the flow scales with the hole area and the absolute pressure: a 1 mm hole at 7 bar loses about 1.
How the compressed air leak cost calculator works
Air escapes a hole at sonic speed, so the flow scales with the hole area and the absolute pressure: a 1 mm hole at 7 bar loses about 1.2 litres of free air a second, a 3 mm hole nearly 11. Compressing air takes about 0.1–0.13 kWh per cubic metre at 7 bar, so the leak’s yearly volume times that energy times your tariff is its cost — often hundreds a year per hole, and plants typically leak 20–30% of what they compress.
Formula: flow (L/s) ≈ 1.2 × d² × (P + 1) ÷ 8; cost = flow × hours × specific energy × tariff
Worked examples
| Inputs | Cost per year | Note |
|---|---|---|
| A 1.5 mm leak at 7 bar, 6,000 h, 0.25/kWh | 1,750 | 2.7 L/s; about 1,750 a year |
| A 3 mm leak | 6,159 | 10.8 L/s |
| Ten 1 mm leaks at 6 bar, 8,000 h | 4,355 | 10.5 L/s together |
FAQFrequently asked questions
How do I find the equivalent hole size?
Most leaks are not round holes; the equivalent diameter is what an ultrasonic leak detector reports, or what you infer from the hiss — audible leaks are typically 1 mm or more. Fittings, hoses and quick couplings are the usual culprits.
Why is compressed air so expensive?
Because compressing it is inefficient: about 90% of the electricity becomes heat, and only a fraction of the remaining energy does work at the tool. Leaks waste the whole chain.
How much do plants leak?
Surveys typically find 20–30% of compressed air lost to leaks in plants without a programme, under 10% in well-managed ones. Fixing leaks is usually the cheapest energy saving available.
Does lowering the pressure help?
Yes, twice over: leak flow falls with absolute pressure, and every bar reduced saves about 7% of compressor energy. Run at the lowest pressure the equipment needs.
Where these figures come from
- Nakajima (1988) — Introduction to TPM — the origin of Overall Equipment Effectiveness and its six big losses
- Health and Safety Executive — the UK workplace safety regulator
Last checked: September 2026. Definitions follow standard operations-management practice; where plants commonly differ, the page says so.