How to calculate Ao5 and Ao12
Cubeathon guide · Reviewed October 2026
An Ao5 (average of 5) is how cubers measure speed: five solves, the best and worst dropped, the middle three averaged. It's the format of most events at WCA competitions, which is why a timer that calculates it the same way matters.
This guide shows the calculation step by step, including the rules for +2 and DNF, with examples you can check by hand.
What Ao5 and Ao12 mean
A single solve can be lucky; an average shows your real level. Ao5 is your last five solves with the best and worst removed. Ao12 is your last twelve with the best and worst removed: more solves, so it moves less and shows your level more steadily.
Dropping the extremes is what makes these “trimmed” averages: one great or terrible solve can't pull the number around.
How to calculate an Ao5
- Take your five solves and apply penalties first: a +2 adds two seconds to that solve.
- Remove the fastest solve.
- Remove the slowest solve. A DNF always counts as the slowest.
- Add the three that are left and divide by 3.
- Round to the hundredth of a second.
If a DNF is still among the three after removing the slowest (that is, there were two DNFs), the whole average is a DNF.
Worked examples
A clean average
12.41 · 10.98 · 13.05 · 11.62 · 14.20
Drop 10.98 (best) and 14.20 (worst). (12.41 + 13.05 + 11.62) ÷ 3 = 37.08 ÷ 3 = 12.36.
Ao5 = 12.36
With a +2
11.20 · 12.35 (+2) · 10.90 · 12.80 · 11.75
The +2 makes 12.35 count as 14.35, now the worst. Drop 10.90 and 14.35. (11.20 + 12.80 + 11.75) ÷ 3 = 35.75 ÷ 3 = 11.9166…, rounded to 11.92.
Ao5 = 11.92
With one DNF
12.10 · DNF · 11.40 · 13.30 · 12.70
The DNF counts as the worst solve and is dropped, along with 11.40. (12.10 + 13.30 + 12.70) ÷ 3 = 38.10 ÷ 3 = 12.70.
Ao5 = 12.70
With two DNFs
12.10 · DNF · 11.40 · DNF · 12.70
Only one solve can be dropped as the worst, so the second DNF stays in, and an average containing a DNF is a DNF.
Ao5 = DNF
Ao12, Ao100 and mean of 3
- Ao12 — drop the single best and single worst, average the other ten. One DNF is dropped as the worst; two make it a DNF.
- Ao100 — drop the five best and the five worst, average the other ninety. Up to five DNFs can be dropped.
- Mean of 3 (Mo3) — nothing is dropped: the plain average of your last three. Any DNF makes it a DNF.
Current and best averages
Your current Ao5 uses your last five solves and changes after every solve. Your best Ao5 is the lowest of every run of five consecutive solves in the session.
Rounding
Single solves are shown to the hundredth with the extra digits cut off (12.678 shows as 12.67). Averages are rounded to the nearest hundredth (11.9166… becomes 11.92), the same convention WCA results use.
Where Cubeathon shows them
- On the timer, your averages update after every solve; the drawer's Stats tab adds the session trend.
- The Performance page lists current and best Ao5 and Ao12, mean of 3, session mean, σ and more for the active session.
- The Compete page shows your best Ao5 and Ao12, ready to share.
Only solves timed on Cubeathon's timer count. Imported and typed-in times stay in your history but don't enter averages or PBs. Each puzzle and session has its own averages.
Want to bring yours down? See how to improve your Ao5 and what counts as a good time.