What is a double hit rate?

It is the percentage of darts thrown at a double that actually land in the double bed to finish a leg. It is the single most important checkout statistic in darts and is tracked by every professional player.

How is the finish probability calculated?

Each dart at a double is an independent Bernoulli trial. The probability of missing all of them is (1 − rate) raised to the number of attempts, so the chance of at least one hit is 1 minus that. The tool multiplies by attempts across your visits.

What is the expected number of attempts?

For a per-dart success probability p, the expected number of darts until your first double is 1 divided by p (a geometric distribution mean). A 25% hit rate means you expect to need about four attempts on average.

Is this realistic for a real leg of darts?

It models the checkout phase only and assumes you have already reduced your score to a finishable double. It treats each double attempt as independent, which is a good approximation for benchmarking practice.

What hit rate should I aim for?

Recreational players often sit at 10–20%, strong club players at 25–35%, and televised professionals frequently average above 40%. Tracking and improving this number is the fastest route to winning more legs.

What is the Darts Scoring Probability Calculator?

Enter your average double-hit rate and the target score to compute the probability of finishing a leg of darts within a given number of visits — useful for practice benchmarking and checkout planning. It runs free in your browser on Gera Tools, with nothing uploaded.

Darts Scoring Probability Calculator

Name: Darts Scoring Probability Calculator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

Get one useful tool a week

Like this tool? Enter your email and we'll send you one genuinely useful Gera tool a week — plus a link to come back to this one. No spam, one-click unsubscribe any time.

A leg of darts is usually decided at the double. This calculator turns your double hit rate into the probability of finishing within a set number of attempts, so you can benchmark practice and set realistic checkout goals.

How it works

Each throw at a double is treated as an independent Bernoulli trial with success probability p (your double hit rate). If you take n attempts in total, the probability of hitting at least one is:

P(finish) = 1 − (1 − p)^n

The total number of attempts is your number of visits multiplied by the darts at a double you take per visit. The expected number of attempts until your first successful double follows a geometric distribution with mean 1 / p.

Worked examples

25% hit rate, 1 dart at the double per visit:

Visits (darts)	P(at least one finish)
1	25%
2	43.8%
3	57.8%
4	68.4%
6	82.2%

At 25%, on average you need 4 attempts to land a double (geometric mean = 1/0.25).

Comparing hit rates — for example:

Hit rate	Expected attempts to finish	P(finish in 3 darts)
15%	~6.7	38.6%
25%	4.0	57.8%
35%	~2.9	72.5%
45%	~2.2	83.3%

Going from 20% to 30% does roughly halve your expected number of attempts, which shows why targeted double practice has the highest leverage of any drill.

What “darts at a double per visit” means

In a checkout visit you may throw 1, 2, or all 3 darts at a double depending on how many darts you need to reduce the score first. A player leaving 40 (D20) at the start of a visit gets 3 darts at the double. A player who needs 2 darts to reach a double leaves only 1 dart at it. Changing this field lets you model the difference: for example, setting 3 darts at the double and 4 visits gives over 99% finish probability even at a modest 25% hit rate.

How to use this for practice

Measure your double hit rate in a practice session: count the number of times you hit a double out of your total attempts at one. Then use this tool to see what finish probability that rate produces in your typical checkout visits per leg. If the probability is lower than your win rate goals require, you know what to practise.

A common recreational benchmark: reaching 25% hit rate at D20 specifically gives you a roughly 58% chance of finishing in 3 darts when you arrive at 40 — a coin flip that improves sharply with each percentage point above that.