# House edge and volatility calculator for blackjack hands

> Work out the expected loss over N hands of blackjack from a house edge and a stake, with the formula shown and six worked examples. Educational, not a forecast.

Source: https://seatcheck.uk/house-edge-calculator/
Updated: 2026-11-13

Expected loss in pounds equals the number of hands times the stake times the house edge. At an example edge of 1%, 100 hands at £5 cost an expected £5.00, and 1,000 hands at £10 cost £100.00. The result is an average, not a forecast, and real sessions swing around it. This is an educational calculation, not a reason to play.

## Calculate an expected loss

Enter the house edge as a percentage, the stake in pounds and the number of hands. The tool returns the total staked and the expected loss. If the tool does not load, use the formula and the table below.

**Six worked examples at an example house edge of 1% · calculated from the formula on this page · illustrative input, not the edge of any table**

| Hands (N) | Stake (s) | Total staked | Expected loss at 1% |
|---|---|---|---|
| 100 | £5 | £500.00 | £5.00 |
| 100 | £10 | £1,000.00 | £10.00 |
| 500 | £5 | £2,500.00 | £25.00 |
| 500 | £10 | £5,000.00 | £50.00 |
| 1,000 | £5 | £5,000.00 | £50.00 |
| 1,000 | £10 | £10,000.00 | £100.00 |

The 1% is a round number chosen so the arithmetic is easy to follow. It is not the house edge of any table. Replace it with the figure a studio publishes for the variant and rules you are looking at.

**Takeaway:** the loss grows with the total staked, which is hands times stake.

## The formulas

- Total staked = N × s, with N hands and a stake s in pounds.
- Expected loss = N × s × h, where h is the house edge as a decimal, so 1% is 0.01.
- Typical spread around that average = σ × s × √N, where σ is the standard deviation of the result of one hand.

The spread formula is shown for completeness. The field for σ stays hidden until a sourced value is entered in our fact log with its date, and none is held yet, so the calculator gives no spread today.

**Takeaway:** only the expected loss is calculated here; the spread waits for a sourced figure.

## Where the house edge comes from

The studio publishes a return to player for a variant, and the house edge is 100% minus that figure.

A published figure applies to the conditions the studio states, such as the strategy assumed. Read those conditions and the date. No provider figure has been read for this site yet.

The [rule variants page](https://seatcheck.uk/blackjack-rule-variants-snapshot/) will hold the rules that sit behind each figure. For a plain definition, see [house edge](https://seatcheck.uk/house-edge/); for return to player in blackjack, see [RTP in blackjack](https://seatcheck.uk/rtp-in-blackjack/).

**Takeaway:** a house edge means something only with the rules it was stated for.

## What the sum cannot tell you

It is an average over a long run of sessions, so one session can end well above or below it.

It does not rescue a betting system: whether basic strategy changes the edge is covered in [basic strategy and the house edge](https://seatcheck.uk/does-basic-strategy-cut-the-house-edge/), and the arithmetic of doubling after a loss in [the Martingale at blackjack](https://seatcheck.uk/does-the-martingale-work-at-blackjack/).

Gambling is a risk, not an income, and no figure here makes it a way to earn. For limits and support, see [staying in control at a live blackjack table](https://seatcheck.uk/safer-live-play/).

**Takeaway:** treat the figure as the cost of playing, never as a target.

## FAQ

**What does a house edge of 1% mean?**

On average, the casino keeps 1% of the total amount staked. Over £1,000 of total stakes that is £10 on average. A single session can finish well above or well below that average.

**How is house edge related to RTP?**

They are two sides of one number: house edge equals 100% minus the return to player. An RTP of 99% means a house edge of 1%, as long as both are stated for the same conditions.

**Why is the stake multiplied by the number of hands?**

Each hand is a fresh stake. The total staked is hands times stake, and that total, not your balance, is what the house edge is applied to.

**Does the calculator predict my result?**

No. It gives an average over a long run of sessions. It cannot say what will happen in yours, and it is not a guide to how much you can afford to play.