Basketball Efficiency Calculator Formula

Understand the math behind the basketball efficiency calculator. Each variable explained with a worked example.

Use the Basketball Efficiency Calculator

Formulas Used

Efficiency Rating

efficiency = points + rebounds + assists + steals + blocks - missed_fg - missed_ft - turnovers

FG%

fg_pct = round(fgm / fga * 1000) / 10

FT%

ft_pct = round(ftm / fta * 1000) / 10

Positive Contributions

positive_plays = points + rebounds + assists + steals + blocks

Variables

VariableDescriptionDefault
pointsPoints22
reboundsRebounds8
assistsAssists5
stealsSteals1
blocksBlocks1
fgaField Goal Attempts18
fgmField Goals Made9
ftaFree Throw Attempts6
ftmFree Throws Made4
turnoversTurnovers3
missed_fgDerived value= fga - fgmcalculated
missed_ftDerived value= fta - ftmcalculated

How It Works

How Basketball Efficiency Is Calculated

Formula

EFF = (PTS + REB + AST + STL + BLK) - (Missed FG + Missed FT + TOV)

This simple formula sums positive contributions and subtracts negative ones.

Context

An efficiency rating of 15+ per game is very good, and 20+ is All-Star caliber. This is a simpler version of PER (Player Efficiency Rating).

Worked Example

22 pts, 8 reb, 5 ast, 1 stl, 1 blk, 9/18 FG, 4/6 FT, 3 TOV.

points = 22rebounds = 8assists = 5steals = 1blocks = 1fga = 18fgm = 9fta = 6ftm = 4turnovers = 3
  1. 01Positive = 22 + 8 + 5 + 1 + 1 = 37
  2. 02Missed FG = 18 - 9 = 9
  3. 03Missed FT = 6 - 4 = 2
  4. 04Negative = 9 + 2 + 3 = 14
  5. 05EFF = 37 - 14 = 23

Frequently Asked Questions

What is a good efficiency rating?

In the NBA, 10-15 is average for starters, 15-20 is very good, and 20+ is elite. League leaders typically average 25-30+.

How is this different from PER?

PER (Player Efficiency Rating) is a more complex formula that accounts for pace, league averages, and per-minute production. Simple EFF is a quick approximation.

Does this account for defense?

Only partially through steals and blocks. Many defensive contributions (positioning, contests, communication) are not captured by box scores.

Ready to run the numbers?

Open Basketball Efficiency Calculator