Darts Checkout Calculator
Find checkout combinations for any remaining score in 501 darts.
Shows optimal 1, 2, and 3-dart double-out finishing routes from 170 down to 2.
The structure of 501 darts
The standard professional darts game is 501. Each player starts at 501 points and counts down to exactly zero. The first to hit zero (with the final dart landing in a double or the bullseye) wins the leg.
If you go below zero (a “bust”), the throw doesn’t count and you return to your previous score. Going to exactly 1 is also a bust — you can’t finish on a single. The final dart must land in a double or the bull (which counts as a double 25).
This rule structure creates the famous “checkout” problem: from any given score, what’s the optimal 1, 2, or 3-dart sequence to finish on a double?
The dartboard layout
Understanding the board is essential. A standard dartboard:
- 20 numbered segments (1-20 around the board)
- Each segment has a single (most of the area), a double (outer thin ring), and a treble/triple (inner thin ring)
- Bullseye: 50 (inner bull) + 25 (outer bull)
- Treble 20 (T20) = 60 points (highest single-dart score)
- Three darts maximum per turn = 180 max (T20, T20, T20)
The board layout was designed by Brian Gamlin in 1896 to punish inaccuracy. Numbers are arranged so that missing a high segment lands you in a low one: 20 is flanked by 1 and 5; 19 by 7 and 3.
The highest possible checkout: 170
The maximum 3-dart finish is 170:
- T20 (60) + T20 (60) + Bull (50) = 170
Higher scores require 4+ darts. Anyone shouting “one hundred and EIGHTY!” has just thrown a maximum visit (T20, T20, T20). Anyone hitting a 170 finish is performing the highest possible finishing combination.
Impossible checkouts
Some scores cannot be finished in 3 darts. These are called “bogey numbers”:
| Score | Why it’s impossible |
|---|---|
| 169 | Can’t combine to leave a double |
| 168 | Best is T20+T20+? — leaves 48, then need… but 48 is D24 which doesn’t exist |
| 166 | Combinations don’t work out |
| 165 | Best 2 darts leave odd remainders |
| 163 | Mathematical structure prevents 3-dart finish |
| 162 | Same constraint |
| 159 | Tricky number |
If you have one of these scores with 3 darts left, you must “setup” — leave a workable number for next visit. From 169, a common setup is T20+S19 (79), leaving 90 (T20+D15 or T18+D18).
The professional’s favorite finish: 32
Professional players prefer to finish on D16 (32):
- If you hit D16: you’ve won
- If you miss into single 16: you have 16 left, which is D8
- If you miss D8: you have 8 left, which is D4
- If you miss D4: you have 4 left, which is D2
- If you miss D2: you have 2 left, which is D1
The 16-8-4-2-1 “power of 2” path means each miss leaves a cleanly halved double. This is why pros set up to leave 32.
By contrast, miss a D17 and you have 17 left (need T7+D? or another path requiring 2 darts). The clean halving doesn’t work.
Other preferred finishing doubles
| Final double | Why it’s good |
|---|---|
| D20 (40) | Most common; familiar territory |
| D16 (32) | Clean halving on misses |
| D8 (16) | Halves to D4, D2, D1 |
| D10 (20) | Direct miss into 5 or 1 (single) |
| Bullseye | High-value target; central |
| D12 (24) | Halves to D6, D3 (then S3, D… breaks down) |
Avoid finishing on doubles with odd “ladders” (D11, D13, D17) — misses leave awkward remainders.
The classic finishing routes
The most-used checkouts among professional players:
| Score | Optimal | Pro favorite |
|---|---|---|
| 170 | T20, T20, Bull | T20, T20, Bull |
| 167 | T20, T19, Bull | T20, T19, Bull |
| 161 | T20, T17, Bull | T20, T17, Bull |
| 160 | T20, T20, D20 | T20, T20, D20 |
| 158 | T20, T20, D19 | T20, T20, D19 |
| 130 | T20, T18, D8 | T20, T20, D5 (avoid; D20 better) |
| 120 | T20, S20, D20 | T20, S20, D20 |
| 100 | T20, D20 | T20, D20 (or T18+D23… wait, D23 doesn’t exist; T20+D20) |
| 81 | T19, D12 | T19, D12 |
| 60 | S20, D20 | 20, D20 |
| 40 | D20 | D20 |
| 32 | D16 | D16 |
Checkout percentage — the key pro stat
Professional darts players’ “checkout percentage” tracks the success rate of attempted finishing visits. Top players:
| Player | Career checkout % |
|---|---|
| Phil Taylor (peak) | 47-50% |
| Michael van Gerwen | 41-45% |
| Luke Humphries | 38-42% |
| Average PDC pro | 33-38% |
| Average county-level player | 20-30% |
| Average pub player | 5-15% |
| Beginner | 1-5% |
A 40% checkout percentage means hitting roughly 2 out of 5 attempted finishes. The remaining 60% leave the opponent an opportunity.
The 9-darter — darts’ perfect game
A “9-dart finish” is the minimum-darts checkout from 501 — analogous to a bowler’s perfect game. The mathematical structure:
Standard 9-darter route:
- T20, T20, T20 = 180 (321 left)
- T20, T20, T20 = 180 (141 left)
- T20, T19, D12 = 141 (zero — checkout)
Or:
- T20, T20, T20 = 180 (321 left)
- T20, T20, T20 = 180 (141 left)
- T17, T18, Bull = 141 (zero)
The first 9-darter on UK television: Paul Lim, 1990 World Championship. Since then, 9-darters have become much more common as players have improved. Phil Taylor hit 11 televised 9-darters. Michael van Gerwen has hit several including back-to-back.
The cricket variant
In addition to 501, “Cricket” is a popular American darts game where players score by hitting numbers 15-20 and the bull three times each. Different strategy, different math. Many calculators specifically handle 501 because it’s the standard professional format.
Tactical considerations
Setup darts: when you can’t finish in 3 darts (e.g., 169, 168, 166), you “set up” by leaving a workable number for next visit. Common setups:
- From 169: leave 32 (T20+S20+S? = 60+20+? to leave 32, but need: aim for 137 to leave 32)
- From 99: T19+S10 leaves 32
Opponent watching: in tournament play, watch your opponent’s average. If they’re averaging 100/visit, you have approximately 5 visits before they finish 501. Plan accordingly.
Stress mathematics: under pressure, players often “freeze” on calculating finishes. Knowing common checkouts (170, 160, 100, 81, 60, 40, 32, 24) reduces cognitive load.
Practice routines
Top players practice checkouts intentionally:
- Around the clock: hit each double 1-20 in order with 3 darts
- 170 challenge: hit T20, T20, Bull as many times as possible in 10 minutes
- Setup practice: from various scores, practice leaving 32 or 40
- Treble 20 grouping: 100 darts at T20 to track accuracy
Phil Taylor reportedly practiced 6-8 hours per day at his peak. Most professional players practice 2-4 hours daily.
Bottom line
501 darts requires finishing on a double or the bull. Highest 3-dart checkout is 170 (T20+T20+Bull). Some scores (169, 168, 166, 165, 163, 162, 159) cannot be finished in 3 darts. Professional players prefer setting up to leave 32 (D16) because the halving sequence 32→16→8→4→2→1 means each miss leaves a workable double. Top professionals hit 40-50% of their checkout attempts. Knowing common checkouts (170, 100, 81, 60, 40, 32) significantly improves match performance — practiced checkout routes reduce hesitation under pressure.