Scorecard scaling calculator for credit decisions
Set the base score, the odds at that score and the points to double the odds. Get the factor, the offset and what every score means.
Scaling results
score = 487.12 + 28.85 × ln(odds)
Probability of going bad by score
Score and probability table
| Score | Odds to 1 | Probability of going bad |
|---|---|---|
| 540 | 6.25:1 | 13.79% |
| 550 | 8.84:1 | 10.16% |
| 560 | 12.5:1 | 7.41% |
| 570 | 17.7:1 | 5.35% |
| 580 | 25.0:1 | 3.85% |
| 590 | 35.4:1 | 2.75% |
| 600 Base | 50.0:1 | 1.96% |
| 610 | 70.7:1 | 1.39% |
| 620 | 100:1 | 0.990% |
| 630 | 141:1 | 0.702% |
| 640 | 200:1 | 0.498% |
| 650 | 283:1 | 0.352% |
| 660 | 400:1 | 0.249% |
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Once the scale is set, a cut-off on the score is a cut-off on the odds, and the next step is running that cut-off as the live credit decision. Start free
Show formulas
Factor = Points to double odds ÷ ln(2) Offset = Base score − Factor × ln(Good odds at base score) Score = Offset + Factor × ln(Odds to 1) Odds to 1 = e^((Score − Offset) ÷ Factor) Probability of going bad = 1 ÷ (1 + Odds to 1)
This is the usual scaling: a higher score means lower risk, and the odds are good to bad. The probability of going bad is one divided by one plus the odds.
Scorecard scaling
Scorecard scaling sets what each point means by combining a base score, the good-to-bad odds at that score and PDO. The result is a factor and an offset that connect score, odds and probability of going bad.
A fixed scale makes a score cut-off an odds cut-off. Use the result to read scores as odds and probability, then run the cut-off as a live credit decision.
Common questions
What does PDO mean in scorecard scaling?
PDO is the number of points needed to double the good-to-bad odds. It sets how much the score changes when the odds double.
How do you calculate the factor and offset?
The factor is PDO divided by the logarithm of two. The offset is the base score minus the factor multiplied by the logarithm of the base odds.
How do you convert probability of default to a score?
Enter the probability of going bad in the score converter. The calculator uses it to return the score for that probability.
What are base odds in scorecard scaling?
Base odds are the good-to-bad odds at the base score. They anchor the offset used to connect scores with odds.
How does scorecard scaling turn odds into probability?
The probability of going bad is one divided by one plus the good-to-bad odds. The calculator shows this probability for each score in the table and curve.