Forecast accuracy

The forecast is what we planned to sell. Actual is what we sold. The error is the gap between them.

About 5–10 minutes · no sign-up needed

The idea

The forecast is what we planned to sell. Actual is what we sold. The error is the gap between them:

1 − ABS( Forecast − Actual ) ÷ Actual

ErrorHow far off the forecast was, in units, whichever way. Audio: 1,000 − 800 = 200.

ABSTakes away the minus sign. Screen guards: 450 − 500 = −50, and ABS makes it 50.

Accuracy1 minus the error as a share of what sold. Audio: 1 − 200 ÷ 800 = 0.75, so 75%.

100% is spot on. For one product in one store, 70% to 80% is often good; whole categories should be higher.

Try each one in your head first, then open the answer.

1. Audio planned 1,000 and sold 800. What was its error, in units?

1,000 − 800 = 200 units

2. In D4, work out Cases' forecast accuracy, as a decimal (no × 100).

=1-ABS(B4-C4)/C4

3. What was the forecast accuracy for Power banks?

ABS(300 − 400) = 100, then 1 − 100 ÷ 400 = 0.75, so 75%

4. Chargers was spot on. Tap the next most accurate forecast.

Screen guards: off by 50 on 500 sold, 90% accurate.

5. Audio and Power banks were both 75% accurate. Is it the same problem?

No: Audio's bias is +25% and Power banks' is −25%. Accuracy doesn't show which way

Learn it by doing. This lesson is a short hands-on level on Bampaa: see it work, then build and write it yourself, with instant feedback.

About 5–10 minutes · no sign-up needed