Betting Calculators for Odds, Probability, Value and Staking

Betting calculator tools for comparing odds, probability, value and stake size

Thirteen tools for pricing, staking, settlement and risk

Choose a calculator according to the question you need to answer.

Each calculator answers a different pricing, staking or settlement question. Converting odds does not remove margin, implied probability does not establish the underlying probability, and a positive EV result is only as reliable as the probability entered.

Start with the quoted price. Convert it only if necessary, calculate its break-even implied probability and, when prices are available for all mutually exclusive outcomes, estimate the market overround. Expected value requires a separate probability estimate rather than the bookmaker price alone.

The other tools cover stake sizing, Asian handicap settlement, football score modelling, parlays, dutching, closing-line comparison, hedging, payout calculations and bankroll variance. Each tool is intended for a specific calculation and does not replace the market, probability or settlement assumptions behind it.

Which betting calculator should you use?

Match the tool to the immediate calculation rather than relying on one number for the full decision.

Task	What the result means	Calculator
Convert odds	Expresses the same market price in decimal, fractional or American format.	Odds Converter
Calculate implied probability	Shows the break-even probability represented by a quoted price.	Implied Probability Calculator
Remove bookmaker margin	Normalises prices for all mutually exclusive outcomes to estimate proportional no-vig probabilities.	Bookmaker Margin Calculator
Calculate expected value	Estimates expected net profit or loss per unit staked from your probability estimate and the available odds.	Expected Value Calculator
Calculate stake	Converts bankroll size and estimated edge into a controlled stake.	Bankroll Staking Calculator
Check handicap settlement	Explains full wins, half wins, pushes, half losses and full losses.	Asian Handicap Calculator
Model football scores	Estimates correct-score probabilities from expected home and away goal rates.	Poisson Score Calculator
Combine parlay legs	Multiplies decimal prices to show combined parlay odds, total return and profit.	Parlay Calculator
Split a dutching stake	Allocates a total stake across mutually exclusive selections to target the same gross return.	Dutching Calculator
Measure closing-line value	Compares the entry price with the selected closing reference for the same market and settlement rules.	Closing Line Value Calculator
Calculate a hedge	Estimates the opposing stake required to balance two mutually exclusive outcomes.	Hedge Bet Calculator
Calculate payout	Separates stake, total return and net profit for a quoted price.	Betting Payout Calculator
Simulate bankroll variance	Shows how repeated wins and losses can produce different bankroll paths under the same assumptions.	Bankroll Variance Simulator

How each calculator works

Definitions, formulas, practical examples and the main limitation of each method.

Convert odds

Odds Converter

Open Odds Converter

Odds conversion changes the notation of a price without changing its underlying payout or implied probability. It is useful when comparing bookmakers or markets that use different display formats.

Fractional a/b → Decimal = 1 + a ÷ b
Positive American +A → Decimal = 1 + A ÷ 100
Negative American odds → Decimal = 1 + 100 ÷ |American odds|

Decimal odds of 2.50 are equivalent to fractional odds of 3/2 and American odds of +150. American odds of −200 convert to decimal odds of 1.50.

What conversion does not do

Changing the display format does not remove bookmaker margin or show whether the price has positive expected value.

Calculate implied probability

Implied Probability Calculator

Open Implied Probability Calculator

Implied probability is the break-even percentage represented by a quoted price. It provides a market benchmark before you introduce your own forecast.

Implied probability (%) = 1 ÷ decimal odds × 100

Decimal odds of 2.50 imply 40%. Odds of 1.80 imply approximately 55.56%. Your estimated probability must exceed the relevant break-even point before the price can show positive theoretical value.

Implied does not mean true

When quoted prices cover all mutually exclusive outcomes, their raw implied probabilities normally include bookmaker margin and may add up to more than 100%.

Remove bookmaker margin

Bookmaker Margin Calculator

Open Bookmaker Margin Calculator

Bookmaker margin is calculated across every mutually exclusive outcome in the same market. The calculator first converts each price into raw implied probability and then normalises the total.

Overround (%) = [Σ(1 ÷ decimal odds) − 1] × 100
Proportional no-vig probability = raw probability ÷ total raw probability

In a two-way market priced at 1.91 and 1.91, each selection has a raw implied probability of approximately 52.36%. The combined total is about 104.71%, giving an overround of approximately 4.71%. Proportional normalisation returns 50% for each side.

Method used

This calculator uses proportional normalisation. Alternative de-vig methods can produce slightly different estimates, particularly in uneven markets.

Calculate expected value

Expected Value Betting Calculator

Open Expected Value Calculator

Expected value compares your independently estimated probability with the available price. The result is the expected net profit or loss per unit staked under that probability assumption; it does not describe the chance that one individual bet will win.

EV per unit staked = estimated probability × decimal odds − 1

At decimal odds of 2.20 and an estimated probability of 47%, EV equals 0.47 × 2.20 − 1 = 0.034. That is an expected net profit of 0.034 units per 1 unit staked, or +3.4%.

The forecast is the critical input

A mathematically correct EV result can still be misleading when the probability estimate is poorly calibrated, based on a small sample or adjusted after seeing the odds.

Calculate stake

Bankroll Staking Calculator

Open Bankroll Staking Calculator

A staking calculator converts bankroll size, price and estimated probability into a controlled level of exposure. It should be used after the price and probability assumptions have been checked.

Full Kelly fraction = (b × p − q) ÷ b
b = decimal odds − 1, p = win probability, q = 1 − p

At odds of 2.20 with a 47% estimated probability, full Kelly is approximately 2.83% of bankroll. Quarter Kelly reduces the theoretical stake to approximately 0.71%.

If the Kelly fraction is zero or negative, the calculation does not indicate a bet.
Fractional Kelly reduces exposure when the probability estimate is uncertain.
Correlated bets should also be controlled by a separate total-exposure limit.

Stake size is not a confidence label

A larger mathematical stake is only justified when the probability estimate and the available price support it.

Check Asian handicap settlement

Asian Handicap Calculator

Open Asian Handicap Calculator

Quarter handicaps split the stake equally between two neighbouring lines. The calculator shows whether the final score produces a full win, half win, push, half loss or full loss.

−0.25 = half the stake on 0 and half on −0.5
+0.75 = half the stake on +0.5 and half on +1.0

A team backed at −0.25 produces a half loss when the match ends in a draw: the 0 portion is refunded and the −0.5 portion loses. A team backed at +0.75 produces a half loss when it loses by exactly one goal.

Check the market rules

Confirm which team receives the handicap and whether settlement uses regulation time only or includes extra time.

Calculate Poisson score probabilities

Poisson Correct Score Calculator

Open Poisson Score Calculator

A basic Poisson model estimates the probability that a team scores exactly zero, one, two or more goals from an expected goal rate. Home and away distributions can then be combined into correct-score probabilities.

P(X = k) = e^−λ × λ^k ÷ k!
Correct-score probability = home score probability × away score probability

If the expected home scoring rate is 1.60 and the away rate is 1.10, the probability of 2–1 is calculated by multiplying the probability of exactly two home goals by the probability of exactly one away goal.

The model assumes fixed scoring rates during the match.
A basic version treats the teams' goal totals as independent.
Red cards, tactical changes, lineups and game state are not automatically incorporated.
Some low-scoring draws can be misestimated without additional dependence corrections.

Read the full distribution

The most likely correct score is still only one outcome within a wider probability distribution.

Combine multiple selections

Parlay Calculator

Open Parlay Calculator

A parlay combines multiple selections into one bet. Use it to calculate the combined decimal price, total return and net profit when all required legs win.

Combined decimal odds = odds₁ × odds₂ × ... × oddsₙ
Total return = stake × combined decimal odds
Net profit = total return − stake

Odds of 1.80, 2.10 and 1.65 combine to 6.237. A 20-unit stake returns 124.74 units, including 104.74 units of net profit.

Correlation and settlement still matter

Multiplying odds calculates the parlay payout; it does not establish the legs' joint probability. Correlation and void or pushed selections can change the effective risk or settled price.

Split a stake across outcomes

Dutching Calculator

Open Dutching Calculator

Dutching splits one total stake across mutually exclusive selections so that each covered winner targets the same gross return.

Weightᵢ = (1 ÷ oddsᵢ) ÷ Σ(1 ÷ odds)
Stakeᵢ = total stake × weightᵢ
Equal gross return = total stake ÷ Σ(1 ÷ odds)

With 100 units across odds of 2.20 and 3.40, the stakes are about 60.71 and 39.29 units. Either covered winner returns about 133.57 units.

Only included outcomes are covered

An omitted mutually exclusive outcome can still produce a full loss of the dutched stake.

Compare entry price with the close

Closing Line Value Calculator

Open CLV Calculator

Closing-line value compares the recorded entry price with a selected closing reference for the same selection and settlement rules. Higher entry odds mean a more favourable price than that reference.

Price-ratio CLV (%) = (bet odds ÷ closing odds − 1) × 100
Raw implied probability = 1 ÷ decimal odds

A bet taken at 2.10 that closes at 1.95 has price-ratio CLV of about +7.69%. The raw price-implied figures are about 47.62% at entry and 51.28% at the close.

Use the same market definition

CLV measures price movement. A change in raw implied probability does not prove that the outcome's underlying probability changed by the same amount.

Balance an open position

Hedge Bet Calculator

Open Hedge Bet Calculator

A two-outcome hedge adds an opposing position. This formula targets the same net result across two fully opposing outcomes with compatible settlement rules.

Equal-profit hedge stake = original stake × original decimal odds ÷ hedge decimal odds

A 100-unit bet at 2.50 and an opposite price of 1.80 require a hedge of about 138.89 units. Either covered result then produces about 11.11 units of net profit.

Not every market is two-way

Three-way outcomes, pushes, commissions, dead heats or different settlement periods require a different hedge structure.

Calculate return and profit

Betting Payout Calculator

Open Betting Payout Calculator

A payout calculator separates total return from net profit. Total return includes the original stake; net profit does not.

Total return = stake × decimal odds
Net profit = stake × (decimal odds − 1)

A 50-unit stake at 1.90 returns 95 units if it wins, of which 45 units are net profit.

Settlement can alter the result

Pushes, partial Asian settlements, dead heats, commissions, void selections or deductions require additional settlement logic.

Model bankroll paths

Bankroll Variance Simulator

Open Bankroll Variance Simulator

A bankroll variance simulation repeats the same betting assumptions across many sequences to show the range of possible ending bankrolls and drawdowns.

Win: bankrollₜ₊₁ = bankrollₜ + stake × (decimal odds − 1)
Loss: bankrollₜ₊₁ = bankrollₜ − stake
Expected net profit per 1 unit staked = p × decimal odds − 1

At odds of 1.90 and p = 55%, expected net profit is +0.045 units per unit staked, or +4.5%. Finite simulated paths can still finish negative.

The assumptions define the simulation

Probability, price, staking and dependence assumptions determine the output distribution; it is not a forecast of the next bankroll path.

Calculation standards used on Odds2Win

How results are interpreted across the calculator collection.

Decimal odds are the internal reference format

Other formats are converted before probability, expected value or staking calculations are performed.

Raw implied probability is calculated before margin removal

Prices for all mutually exclusive outcomes are required when estimating overround and proportional no-vig probabilities.

Quarter handicaps are divided into equal halves

A −0.25, +0.25, −0.75 or +0.75 selection is settled as two equal stakes on neighbouring lines.

Kelly results depend on the probability entered

The staking output is not an independent recommendation and should be reduced when model uncertainty is high.

Poisson outputs use simplified scoring assumptions

They estimate a distribution from expected goal rates and do not guarantee the most likely displayed score.

Parlay and dutching calculations use prices differently

Parlay prices are multiplied, while dutching stakes are weighted by inverse decimal odds across the covered outcomes.

CLV and hedge comparisons require matched settlement scope

Prices should refer to compatible selections, outcomes and settlement rules before the result is interpreted.

Payout and simulation outputs depend on their definitions

Total return includes the original stake, while bankroll simulations remain conditional on the entered probability, price and staking assumptions.

Displayed values may be rounded

Where supported by the calculator, underlying calculations should use unrounded values before presenting the final result.

Betting calculator FAQ

Important differences between market prices, fair probabilities, value and modelling.

Which betting calculator should I use first?

Start with the odds converter only when the displayed format is unfamiliar. Then calculate implied probability. When the full set of prices is available, estimate the bookmaker margin before comparing the market with your own probability.

Is implied probability the same as the underlying probability?

No. Implied probability is the break-even percentage represented by the quoted odds. It can include bookmaker margin and may differ from the outcome’s underlying probability.

Do no-vig probabilities automatically represent fair odds?

No. Margin removal produces a method-dependent market estimate. Proportional normalisation preserves the relative shape of the quoted prices, but it does not establish the outcome's underlying probability or guarantee that the resulting fair odds are accurate.

Does positive expected value guarantee profit?

No. Positive expected value means positive expected net profit per unit staked under the probability entered. Realised results can still be negative over individual bets or finite sequences.

Can the Poisson calculator predict the exact final score?

It estimates the probability of multiple scorelines. The highest-probability score is not a prediction that the match will necessarily finish with that result.

What does positive closing-line value mean?

Under the price-ratio method used here, positive CLV means the entry price was higher than the selected closing reference for the same selection and settlement rules. It is a price-comparison metric, not a statement that the individual bet should win.

Why can a positive-EV bankroll simulation still finish negative?

Expected value describes an average under the assumptions entered. Finite sequences can still contain losing runs, adverse clustering and drawdowns, so individual simulated paths may finish below the starting bankroll.

Responsible use

These calculators are provided for informational and educational purposes. Betting involves financial risk, results depend on the accuracy of the inputs, and no calculation guarantees a profitable outcome.