How to use the price list rounding rule applier
- Paste one line per item: name, cost and current price, separated by commas.
- Choose the multiple to round to, the amount to subtract (for example 0.01 for endings like 9.99) and the direction: nearest allowed price, up or down.
- Set a margin floor. Lines that fall below it after rounding are flagged.
- Read the before and after prices, the change on each line and the margin before and after, then copy the table or download the CSV.
Formula
allowed prices = k x step - offset, for whole numbers k of 1 or more
nearest: the closest allowed price, ties going up; up: smallest allowed price at or above; down: largest at or below
margin = (price - cost) / price
A step of 1 and an offset of 0.01 allows 0.99, 1.99, 2.99 and so on. An offset of 0 is plain rounding to the step. Running the rule on prices it already produced changes nothing.
Charm endings on six items
With a step of $1, an offset of $0.01 and nearest rounding, the sample prices $14.30, $8.72, $24.18, $12.40, $5.55 and $46.20 become $13.99, $8.99, $23.99, $11.99, $5.99 and $45.99. The changes are -$0.31, +$0.27, -$0.19, -$0.41, +$0.44 and -$0.21, which add up to a drop of $0.41 on a list that totals $111.35.
The margin on the list total goes from 61.52% to 61.38%. The canvas tote has a cost of $6.40, so its margin moves from 55.2% to 54.3%. With a margin floor of 30%, no line is flagged. Choosing up instead of nearest would raise every price that is not already an allowed price.
Direction and the size of the change
Nearest rounding moves a price by less than half a step, up or down. Rounding up always raises prices, which protects margin, and rounding down always lowers them, which gives customers the benefit. With an offset, the allowed prices are not evenly centered on the step, so the largest move can be a little different from half the step.
Very low prices can fall below the smallest allowed price. In that case the smallest allowed price, one step minus the offset, is used.
Checking margins after rounding
Rounding changes margin, sometimes by more than a point on low-priced items. The table shows margin on the price before and after, and the footer figures show the effect on the whole list. Items below your floor are flagged so you can choose a different step for them.
Whether a price ending suits your customers is your decision, and prices that must include tax or follow a local rule need extra care. Turn a cost into a price with the Markup Calculator, check one margin with the Profit Margin Calculator, or print the list with the Price List Generator.
Assumptions and limits
- Prices and costs are in the same currency, and a price must be above zero. The cost can be zero.
- The multiple must be at least 0.01 and the amount to subtract must be smaller than it.
- Up to 1,000 lines are read. Amounts are handled in whole cents.
- Tax, discounts and local pricing rules are not modeled.
- Nothing typed here leaves your browser.
Frequently asked questions
How do I round to .95 or .49 instead of .99?
Set the amount to subtract to 0.05 for .95 endings or 0.51 with a step of 1 for .49 endings. The allowed prices are always multiples of the step minus that amount.
Why did a price not change?
It was already an allowed price, such as 9.99 with a step of 1 and an offset of 0.01. The rule leaves allowed prices where they are.
What does the margin floor do?
It marks lines whose margin after rounding is below the percent you set. It does not change any price, so you can review those lines and decide.
Does it round up or down on a tie?
In nearest mode a price exactly halfway between two allowed prices goes up. Choose down if you prefer to favor the customer in those rare cases.