Guide

KPI weighting explained

A weighted scorecard turns several performance measures into one bonus multiplier. The maths takes a minute to learn; the design decisions behind the weights are what decide whether the plan changes anyone’s behaviour.

Reviewed 20 August 2026 · gross estimates, not payroll or tax advice

How weighting works

Short answer

KPI weighting splits a bonus across several measures, so each one contributes a fixed share of the payout. Weights must add to 100%. Each KPI is scored as a percentage of its goal, multiplied by its weight, and the results are summed into a single payout factor that is then applied to the target bonus.

Payout factor = Σ (KPI score × KPI weight)  ·  Bonus = Target × Payout factor
KPIWeightGoalActualScoreContribution
Revenue40%$5.0m$5.4m108%43.2%
Gross margin30%42%40%95%28.5%
Customer retention20%90%93%103%20.6%
Project delivery10%4 launches375%7.5%
Total100%99.8%

On a $15,000 target that is $14,970. A mixed year with one clear miss and two beats lands almost exactly at target — which is what a well-built scorecard is designed to do.

How many KPIs is too many

The most common design fault is not bad weights. It is too many of them.

Number of KPIsSmallest meaningful weightEffect
2–325–30%Every measure clearly matters. Risk: narrow focus, gaming.
4–515–20%The practical sweet spot for most roles.
6–8~10%Individual measures stop influencing behaviour.
9+<10%Effectively a participation award. Scores average toward 100%.
A KPI weighted at 5% is decoration. On a $15,000 target bonus, moving that measure from 80% to 120% of goal — a huge swing in performance — changes the payout by $300 before tax. Nobody reorganises their quarter for $300. If a measure genuinely matters, give it at least 15%; if it does not deserve 15%, take it off the scorecard.

Setting weights that mean something

1
Start from what the role controls. Weighting someone heavily on a number they cannot influence produces resentment, not performance. A regional manager can move regional revenue; they cannot move group EBITDA.
2
Give the primary measure at least 40%. If everything is equally weighted, you have told the employee nothing about priority. A scorecard should be readable as a statement of what matters most.
3
Cap the number of measures at five. Four is usually better.
4
Define the scoring curve, not just the goal. “Revenue: $5m” is incomplete. What does $4.5m score? Is there a threshold below which it scores zero? Is the score capped at 150%?
5
Decide whether measures can offset each other. Should a spectacular revenue year rescue a safety failure? Many plans add a gate or a modifier precisely so that it cannot.
6
Write down the data source. Which report, run when, by whom. Most scorecard disputes are arguments about the number, not about the weight.

Scoring curves matter more than weights

Two scorecards with identical weights can pay very differently, because the way a result converts to a score is a separate design decision.

CurveBehaviourResult at 90% of goal
Linear, no thresholdScore equals result90%
Linear with 80% thresholdZero below threshold, then linear to target50%
Stepped bandsFixed scores per band75% (the “90–95%” band)
Threshold / target / stretchThree anchor points, interpolated between50–60% depending on anchors

The same 90% result scores anywhere from 50% to 90% depending purely on curve design. When someone says their bonus “felt arbitrary”, the curve is usually the reason — not the weights.

See the payout curve guide for how threshold, target and stretch anchors work.

Five weighting mistakes

1
Weights that do not sum to 100%. Sounds trivial; happens constantly when a scorecard is edited mid-year and a measure is dropped without redistributing its weight.
2
Uncapped scores on one measure. If revenue can score 300% while everything else caps at 150%, the scorecard has quietly become a single-measure plan.
3
Correlated KPIs. Revenue at 40% and new bookings at 30% is a 70% bet on the same underlying thing, dressed as diversification.
4
Subjective measures with heavy weights. “Leadership” at 30% converts the scorecard into a rating band with extra steps, and destroys the credibility of the objective measures alongside it.
5
Changing weights after the period starts. Legally possible in most plans; corrosive in practice. If it has to happen, it should only ever move in the employee’s favour.

Frequently asked questions

What is KPI weighting?

Splitting a bonus across several performance measures so that each contributes a fixed percentage of the payout. Weights must add up to 100%. Each KPI is scored against its goal, multiplied by its weight, and the weighted scores are summed into one payout factor.

How do you calculate a weighted bonus score?

Score each KPI as a percentage of its goal, multiply each score by its weight, then add the results. A 108% score at 40% weight contributes 43.2%. The sum of all contributions is the payout factor applied to the target bonus.

How many KPIs should a bonus scorecard have?

Four or five is the practical maximum. Beyond that, individual weights fall below 15% and stop influencing behaviour, because moving a 5%-weighted measure is worth a few hundred dollars on a typical target bonus.

Can KPI weights add up to more than 100%?

They should not. If they do, the scorecard pays above target for average performance, which is almost always an editing error rather than a design choice. Check the weights sum to exactly 100% before the period starts.

Why did a good year produce an average bonus?

Weighted scorecards are designed to average out. A strong result on one measure is offset by a weak result on another, and the payout factor lands near 100%. This is the intended behaviour, not a fault - it is also why heavily weighted primary measures matter.

Should weights be the same for everyone?

No. Weights should reflect what each role actually controls. A sales manager and a finance manager sharing an identical scorecard means at least one of them is being paid on something they cannot influence.

Related tools and guides

Written and reviewed by the BonusPayCalc editorial team. Every formula on this site is shown on the page that uses it, so you can check it against your own plan document. Figures are gross planning estimates and not payroll, tax, legal or HR advice — see methodology.