How much does a compressed air leak cost?

A single 3 mm leak at 7 bar can waste approximately 5–10 L/s of free air. At typical industrial electricity rates, this can cost €1,000–€3,000 per year. Multiple leaks can easily account for 20–30% of compressor energy.

How is air leak flow rate estimated?

For a sharp-edged orifice, Q = C × A × √(2×ΔP/ρ), simplified to Q ≈ C × A × P for choked flow, where C is a discharge coefficient (≈0.65), A is hole area, and P is gauge pressure. At pressures above about 1.9 bar(g), flow is choked (sonic).

What percentage of compressed air is typically lost to leaks?

In well-maintained systems: 5–10%. Average systems: 15–25%. Poorly maintained: 25–40%. Regular leak detection programs can reduce losses to under 10%.

How do I find compressed air leaks?

Methods include: ultrasonic leak detectors (most effective), soapy water on joints, listening during quiet periods, and monitoring compressor run-time when demand is zero. Ultrasonic detectors can find leaks even during production.

How do I calculate the electricity cost of compressed air leaks?

Cost = (leak flow in L/s) / (compressor output per kW) × electricity rate × operating hours. A typical compressor produces about 6–8 L/s per kW. Multiply by 8,760 hours for annual cost.

Free Engineering Tool — #146

Compressed Air Leak Cost Calculator

Estimate the flow rate and annual cost of compressed air leaks based on hole diameter, system pressure, and energy cost.

Q = C × A × P Annual Cost Energy Audit

Results

Annual Leak Cost

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Leak Flow Rate (FAD)

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Power Wasted

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Annual Energy Wasted

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Leak Flow Rate (Choked Flow)

At pressures above ~1.9 bar(g) the flow through a leak orifice is sonic (choked). The simplified formula:

C — discharge coefficient (~0.65 for sharp-edged orifice)
A — hole area = π/4 × d²
P_abs — absolute pressure (gauge + 1.013 bar)

Annual Cost

Leak Cost by Hole Size (7 bar, €0.15/kWh, 6000 h/yr)

Hole ∅	Flow (L/s)	kW	€/year
1 mm	~1.0	0.15	~135
3 mm	~9.1	1.36	~1,224
5 mm	~25.2	3.78	~3,402
10 mm	~100.8	15.12	~13,608

⚠️ Note: Real leaks have irregular geometry; actual flow may differ from orifice model by ±30%. Use these values as estimates for energy audits.

Compressed Air Leak Cost Calculator | Annual Waste | Free Online Tool

Published by Nikolai Shelkovenko on February 15, 2026 February 15, 2026

Results

Leak Flow Rate (Choked Flow)

Annual Cost

Leak Cost by Hole Size (7 bar, €0.15/kWh, 6000 h/yr)