Bowling handicap calculator
Calculate an individual ten-pin bowling handicap from the base score, percentage and league average. Compare rounding per game with rounding once for a series, then add optional scratch scores.
Enter the rules adopted by your league or tournament. The example uses 100% of 220; it is a starting setting, not a universal rule.
Formula and rounding
raw handicap = (base score − average) × percentage / 100
league average = drop fraction(total scratch pins / games)
The zero-minimum option replaces a negative raw handicap with zero. The negative option keeps it. This calculator drops fractional handicap pins toward zero. For example, 31.5 becomes 31 and −9.5 becomes −9. Confirm the event’s policy for negative values.
The two series methods can differ. With an average of 180, base 230 and 75%, the raw handicap is 37.5: three games receive 111 pins when 37 is multiplied by three, or 112 when 112.5 is truncated once. Select the method in the published event rules.
adjusted series score = scratch series total + selected series handicap
When series rounding is selected, only the series total is adjusted; the tool does not invent an allocation of fractional handicap among individual games.
Checked examples
| Inputs | Result |
|---|---|
| Average 165; base 220; 100%; three games; scores 160, 170, 180 | 55 pins per game; 165 series handicap; 510 scratch + 165 = 675 adjusted. |
| Average 185; 90% of 220; per-game rounding | Raw handicap 31.5; per game 31; three-game handicap 93. |
| Average 180; 75% of 230; series rounding | Raw handicap 37.5; three-game handicap 112. |
| 1,495 scratch pins across nine games | Raw average 166.111…; established average used 166. |
| Average 230; 95% of 220 | Zero under the minimum-zero setting; −9 per game if negative handicap is explicitly enabled. |
Using your league rules
- Enter your recognized entering or current league average, or derive one from the relevant pin total and game count.
- Copy the base and percentage from your league or event rules.
- Check above-base treatment and whether fractions are dropped per game or once for the series.
- Enter the series game count and, optionally, one scratch score per game.
Sources and scope
USBC says handicap settings are chosen by the competition and recommends high percentages, including 100%, for more equalized matches. Rule 108a defines the league average using pinfall divided by games with fractional pins removed. Consult USBC Playing Rules and its handicap resources and one- or three-game charts. These sources were checked October 8, 2026.
This individual calculation does not determine an official entering average, eligibility, rerating, sport/challenge conversion, team handicap, vacancy score, substitute-frame credit or event-specific caps. Supported scratch scores are 0–300, percentages 0–100% with up to two decimal places, and series lengths 1–12 games. Handicap-adjusted totals are not automatically capped at 300.
Frequently asked questions
Is 90% of 220 the same as 90% of my average?
No. Subtract your average from 220 first, then multiply that difference by 0.90.
Do tonight’s scores update the handicap immediately?
This tool uses the average you enter for the whole series. Determine when an average or handicap changes from your competition rules.
Can a handicap-adjusted game exceed 300?
The scratch score is limited to 300 here; adding handicap is a separate arithmetic operation. Apply any event-specific score cap externally.
Related tools: Percentage Calculator for percent arithmetic and Win Percentage Calculator for match records.