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Free betting calculators · No account

Stop guessing.
Run the numbers.

20 calculators for back/lay, dutching, arbitrage, EV and stake sizing. Type your odds, get your stake, see the profit before the money leaves your account.

The next step
in sports analysis.

QMW

Quantum Matrix World is a platform that turns advanceds statistical and quantum-inspired models into data-driven sports predictions.


Data Analysis

Smart models

Clearer predictions

Explore Quantum Matrix World

20

Calculators, all free

$0

Forever, no paywall

0

Signups required

3

Odds formats supported

Start here

Back/lay

The matched-betting workhorse. Exact lay stake, liability and both outcomes, with commission built in.

Open

Dutching

Split one bankroll across several selections so every winner pays the same. Add as many runners as you like.

Open

Arbitrage (surebet)

Two-way and three-way arb stakes with the locked profit, worked out for you.

Open

Formulas, not guesswork

Our approach combines three disciplines most calculator sites skip.

1

Quantitative Research

We derive every formula from first principles, including stake sizing, liability, and expected value. We show our working on the page, not just the answer.

2

Software Engineering

Every calculator runs instantly in your browser as you type. There is no server round trip, no account, and nothing to submit.

3

Continuous Improvement

We keep adding calculators and refining the ones we have, based on what our users actually ask for.

The full bench 01 Back/lay Cover a bookmaker bet on the exchange. Lay stake, liability, both outcomes. 02 Back/back Cover a bet with a back bet on a different bookmaker. Two books, guaranteed profit from either outcome. 03 Lay stake / liability What a lay actually risks, before you accept the bet. 04 Dutching Split one bankroll across several selections for an equal return. 05 Odds converter American, decimal, fractional and implied probability — one input, every format. 06 Implied probability Turn any price into the chance it represents, with the vig stripped out. 07 Expected value Your edge per bet in dollars, given your own probability estimate. 08 Kelly criterion Stake sizing from edge and bankroll — full, half and quarter Kelly. 09 Arbitrage (surebet) Two-way and three-way arb stakes with the locked profit. 10 Bonus / free bet value What a free bet is worth in cash after you lay it off. 11 Accumulator / parlay Combined price, payout and the probability you are really taking. 12 Hedging Close out a live position and take a guaranteed number. 13 Lay odds converter The fair price of the opposite outcome, from a single price you already have. 14 Feasibility A conservative probability band and how many attempts a combined bet like this really needs. 15 Overround / hold Add up a market's prices to see the bookmaker's built-in margin, as a percentage of every dollar staked. 16 Middle Bet both sides of a shifted line and see the guaranteed floor against the bonus if the score lands in the middle. 17 Spread converter The price on a point-spread bet in every format, plus a heads-up on push risk for whole-number lines. 18 Strike rate Your actual win rate against the breakeven rate your average price demands. 19 Win / loss record Turn a stretch of bets into net profit, ROI, strike rate and your average winning price. 20 Staking plan Convert a stake between dollars and percentage of bankroll, with a quick-reference unit-size table.

Free tools.
Real math.

No paywall, no login, no email wall in front of a result. Open a calculator and start typing your odds.

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