# Grid Outage Cost Calculator

> Estimate what a power cut costs a business in lost revenue, idle labour, backup running costs and one-off losses, per outage and over a year.

Category: Energy & environment · Applies to: Worldwide · Last updated: 2026-10-29
Interactive calculator: https://calculators.geekmidst.com/calculators/grid-outage-cost-calculator

An outage costs the revenue you never recover, the wages paid while staff cannot work, any backup power you run, and one-off losses such as spoiled stock or restart work.

Also called: Power cut cost calculator, Downtime cost calculator.

## Inputs
- Outage length (unit h; default 4)
- Outages per year (default 3)
- Revenue per operating hour (default 2000; optional)
- Share of that revenue lost for good (unit %; default 50; optional)
- Staff idled (default 10; optional)
- Hourly cost per employee (default 25; optional)
- One-off costs per outage (default 1500; optional)
- Backup power cost per hour (default 0; optional)
- Currency

## Results
- Cost per outage
- Cost per year
- Lost revenue per outage
- Idle labour per outage
- Backup power per outage
- Average cost per outage hour

## Formula

```
Per outage = Revenue per hour × Hours × Lost% + Staff × Hourly cost × Hours + Backup per hour × Hours + One-off costs;  Yearly = Per outage × Outages per year
```

Where:
- Lost%: share of revenue that is not made up later
- Hourly cost: fully loaded labour cost per employee hour

## Worked example
1. Lost revenue: 2,000 × 4 h × 50% = 4,000; idle labour: 10 × 25 × 4 = 1,000.
2. Per outage: 4,000 + 1,000 + 0 + 1,500 = 6,500.
3. Per year: 6,500 × 3 = 19,500.

**Result:** Each 4-hour outage costs about 6,500, or 19,500 a year at three outages.

## What the result means

Compare the yearly cost with the yearly cost of a backup system (fuel, maintenance and capital spread over its life). If backup keeps you trading, rerun with lost revenue and idle labour set to zero and the backup cost per hour filled in.

## Assumptions and limits
- Every outage has the same length and impact.
- Revenue per hour is the average for the hours outages occur.
- Reputational damage, contract penalties and safety risks are not quantified.

## Questions

### Why not count all revenue as lost?

Some customers simply come back later. Counting only revenue that is never recovered avoids overstating the cost.

### Should I include salaried staff?

Yes, if they cannot work productively during the outage: you pay them either way, so their idle time is a real cost.

## Related calculators
- [Solar Battery Storage Days Calculator](https://calculators.geekmidst.com/calculators/solar-battery-storage-days-calculator)
- [Break-even Calculator](https://calculators.geekmidst.com/calculators/break-even-calculator)
- [ROI Calculator](https://calculators.geekmidst.com/calculators/roi-calculator)

Source: GM¹X CalcVerse — https://calculators.geekmidst.com/calculators/grid-outage-cost-calculator