Promotion Lift Calculator

Work out promotion lift instantly with clear inputs, formula shown and shareable results.

About Promotion Lift Calculator

Promotional lift only pays if it exceeds the break-even lift implied by the margin given away. A 20% discount on a 38% margin needs roughly 34% more units just to hold gross profit flat, which is the test most promotion reviews skip.

Formulas

Sales lift

Lift % = (Promotional units - Baseline units) / Baseline units x 100

Break-even lift

Required lift % = (Normal margin / Promotional margin - 1) x 100

Worked example

With the default values below, Promotion Lift Calculator returns Sales lift of 64.29%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Baseline weekly units: 420
Units during the promotion: 690
Promotional discount: 20
Normal gross margin: 38

Results

Sales lift: 64.29%
Lift needed to break even: 68.89%
Margin during the promotion: 22.50%
Lift above or below break-even: -4.60%

Step by step

1Values used
2Sales lift
3Break-even lift
4Sales lift= 64.29
5Lift needed to break even= 68.89
6Margin during the promotion= 22.50
7Lift above or below break-even= -4.60

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What is a fair baseline?

The average of comparable non-promoted weeks, adjusted for seasonality. Using the immediately preceding week usually understates the baseline.

Does forward-buying matter?

Yes. Customers stockpiling during the promotion depress post-promotion sales, so lift should be measured over a window that includes the dip.