- Maths reviewed by Josh Miller
- Tested by Diana Westfield
A slot hit frequency calculator for your own spins. 2,000 spins at 50p, 540 of them paid something: a hit frequency of 27%, a win about every 3.7 spins. You put £1,000 through and got £930 back, so your RTP so far is 93%. Does that mean the slot’s 96% is a lie? Not even close. With medium volatility, the honest range on your RTP runs from about 67% to 119%. The CasinoCalcs calculator is free and shows you that range for any number of spins.
Hit frequency and RTP aren’t the same thing
Hit frequency is how often you win something. RTP is how much comes back on average. They’re independent. One slot can hit on 45% of spins, mostly paying less than the bet. Another can hit on 18% and save it all for a bonus round that pays 200×. Both can be 96% RTP.
A lot of “wins” are losses in disguise. A 40p win on a 50p spin counts as a hit. So a high hit frequency feels good without changing the maths.
Why your RTP swings so much
A single spin on a medium-volatility slot has a spread of about 6 bets. Most spins pay nothing or a little, and a few pay a lot. Average 2,000 of them and the spread shrinks to 6 ÷ √2000 = 0.13 bets, or ±13%, and twice that for a 95% range. Hence 67% to 119%.
| Spins | Low volatility (3) | Medium (6) | High (10) |
|---|---|---|---|
| 1,000 | ±18.6% | ±37.2% | ±62.0% |
| 10,000 | ±5.9% | ±11.8% | ±19.6% |
| 100,000 | ±1.9% | ±3.7% | ±6.2% |
| 1,000,000 | ±0.6% | ±1.2% | ±2.0% |
That’s the 95% margin of error on your measured RTP. A million spins on a high-volatility slot still leaves you ±2%. No player gets there. Testing labs simulate hundreds of millions.
What you can learn from your own spins
Hit frequency settles much faster than RTP, so that number is worth tracking. After a few hundred spins it’s usually within a couple of points. It tells you what kind of slot you’re on: frequent small wins, or long dry spells waiting for a feature.
RTP from your own play is mostly a record of your luck. Use the published figure for planning. The RTP calculator turns it into an expected loss, the slot bankroll calculator shows how long a budget lasts, and the slot simulator lets you watch thousands of spins in seconds.
To see how hit frequency and RTP come out of the reels, try the slot RTP calculator.
A cold session doesn’t mean a slot is due. Each spin is independent. BeGambleAware.org is free and confidential.