How to calculate net run rate, and the two mistakes that flip the sign

Net run rate decides more league tables than anyone would like, and it is calculated wrong more often than anyone would admit — usually by one of two small mistakes that each move the answer a lot.

This post takes the formula from the ICC's own playing conditions, walks through both mistakes, and then works a real example where getting one of them wrong turns a negative NRR positive. That is not an exaggeration for effect; it is the arithmetic.

#The formula in the ICC's words

The ICC Men's T20 World Cup 2026 Playing Conditions define it in clause 16.10.7:

A team's net run rate is calculated by deducting from the average runs per over scored by that team in its group, the average runs per over scored against that team in its group.

Written as a formula, across every counted match in the competition:

NRR = (total runs scored ÷ total overs faced) − (total runs conceded ÷ total overs bowled)

Two things about that are easy to miss. First, it is totals across the tournament, not an average of each match's run rate — you add up all the runs and all the overs first, then divide once. Averaging per-match NRRs gives a different, wrong answer whenever matches have different lengths.

Second, the formula is simple. Both common mistakes are about what goes into it: how you count overs, and which overs you count.

#Mistake 1: overs are not decimals

Clause 17.1 says the ball "shall be bowled from each end alternately in overs of 6 valid balls". So the scorecard notation 15.4 means 15 overs and 4 balls — and 4 balls is four-sixths of an over, not four-tenths.

Type 15.4 into a calculator as a decimal and you have quietly understated the overs, which overstates the run rate. It looks right, because the number on the scorecard and the number in the calculator are the same. That is exactly why it survives.

The reliable way is to convert everything to balls, add up, and divide by six once at the end.

#Mistake 2: all out means the full quota

This is the rule that moves tables. From clause 16.10.7:

In the event of a team being all out in less than its full quota of overs, the calculation of its net run rate shall be based on the full quota of overs to which it would have been entitled and not on the number of overs in which the team was dismissed.

So a side bowled out for 120 in 16.3 overs of a 20-over match is treated as having faced 20 overs, not 16.5. The rule exists so that being bowled out cheaply cannot flatter a run rate — lasting longer is not a penalty, and collapsing is not a shortcut.

If you forget it, a team that was bowled out looks like it scored faster than it did. As the example below shows, that is not a rounding error.

#A worked example

A 20-over tournament. Team A has played two matches:

• Match 1: Team A 160/6 (20 overs) beat Team B 150/8 (20 overs)
• Match 2: Team A 120 all out (16.3 overs); Team C chased it, 121/4 (15.4 overs)

Add up Team A's side of both matches:

• Runs scored: 160 + 120 = 280
• Overs faced: 20 + 20 = 40 — the 16.3 becomes 20, because Team A was all out
• Runs conceded: 150 + 121 = 271
• Overs bowled: 20 + 15.667 = 35.667 — Team C was not all out, so its actual overs count, converted from balls

Then:

• Scoring rate: 280 ÷ 40 = 7.000
• Conceding rate: 271 ÷ 35.667 = 7.598
• NRR = 7.000 − 7.598 = −0.598

Now the same two matches, calculated each of the wrong ways:

Forgetting the all-out rule does not nudge Team A's NRR. It flips the sign, from comfortably negative to slightly positive. In a table where two teams are level on points, that is the difference between going through and going home.

#What does not count

The same clause excludes a few things, and each one is a common source of disagreement.

Super overs. The clause is direct: "The Super Over is not included in the net run rate calculation." A tie decided by a super over counts for points, but the super over's runs and balls stay out of NRR.

Matches without a result. Per the ICC: "Only those matches where results are achieved will count for the purpose of net run rate calculations." An abandoned match with no result contributes nothing — even if one full innings was played.

Rain-affected results. Where a result is achieved using Duckworth/Lewis/Stern, the ICC substitutes adjusted figures rather than the raw scores — crediting the side batting first with the chasing side's par score, or with one run less than the revised target, over the chasing side's overs. It is a specific adjustment tied to DLS, and it only applies if your competition uses DLS at all. Most local cricket agrees a revised target on the day instead.

Forfeits. The clause also covers a team refusing to play: the defaulting side is charged the full 20 overs of its innings in the forfeited match, and the forfeited match's runs and overs are left out of the NRR of the team it was awarded to.

#Your league may play it differently

The ICC text is written for international events. In club, office, school and tape-ball cricket, organisers adjust it all the time — shorter overs, fewer overs, a different treatment of abandoned games, or a rule that ties on points are separated by head-to-head before NRR is looked at.

None of that changes the arithmetic above. It changes the inputs. Before a tournament starts, it is worth writing down three things and agreeing them with every captain:

1. Is a team that is bowled out charged its full quota? The ICC says yes.
2. Do abandoned or no-result matches count toward NRR? The ICC says no.
3. What separates teams level on points — NRR first, or something else?

Settling those in advance is a great deal easier than settling them after the last league match.

#A note on the app I build

I write this as the person who makes Scorra, so treat it as disclosed interest rather than a neutral pick.

Scorra is an offline cricket scorer, and its tournament mode keeps the points table and net run rate up to date after every match. I checked how it calculates NRR against the rules above rather than just repeating the listing: it counts overs in balls rather than decimals — which also means it handles short formats with 4 to 10 ball overs correctly — it charges a side that is bowled out its full quota of overs, and it leaves super overs out. Tournaments are part of Scorra Pro.

If you are calculating by hand instead, the method above is all you need: convert to balls, apply the all-out rule, total everything, and divide once.

#Frequently asked questions