What a price increase actually buys you
A five percent rise lets you lose eight percent of your customers and stay level. A ten percent discount needs twenty two percent more of them.
The short answer
A price increase raises contribution per unit, so you can lose some volume and still end up level. The volume you can afford to lose is the increase in contribution divided by the new contribution, and it is almost always larger than people expect.
The formula
contribution = price - variable cost
new contribution = new price - variable cost
volume you can lose and stay level = 1 - (old contribution / new contribution)
profit change at unchanged volume = units x (new contribution - old contribution)
The comparison worth making is against a discount of the same size. The asymmetry is the point: raising prices is forgiving and discounting is not, and most businesses instinctively believe the opposite.
Worked example
A product at $14.00 with a variable cost of $6.20, currently selling 720 units a month:
contribution = 14.00 - 6.20 = 7.80
raise 5% to 14.70 → contribution = 8.50
can lose 1 - (7.80 / 8.50) = 8.2% of volume and stay level
at unchanged volume: 720 x 0.70 = 504 more profit a month
for contrast, a 10% discount to 12.60 → contribution 6.40
needs 7.80 / 6.40 - 1 = 21.9% more volume just to stay level
The 5% rise adds $504 a month if nobody leaves, and survives losing one customer in twelve if they do. The 10% discount needs nearly a quarter more customers before it breaks even.
Why the asymmetry is so large
Both changes move price by a few percent and contribution by a much larger percentage, because contribution is the small difference between two bigger numbers. On the figures above, a 5% price rise is a 9% contribution rise and a 10% cut is an 18% contribution fall.
The thinner your margin, the more extreme this gets. A business running on 20% contribution is barely affected by losing customers after a rise and destroyed by needing more after a cut.
How to raise a price without losing the customers you want
Change something visible at the same time. A new size, an improved specification, a clearer guarantee. It gives the increase a reason and it gives you something to talk about other than the number.
Give notice to existing customers and honour old pricing for a defined period. Most of the damage from a price rise comes from the surprise rather than the amount.
Raise selectively first. New customers, or one product line, or one segment. That gives you real data about elasticity instead of a theory, and it is reversible.
When not to raise prices
When you are the cheapest option and that is the only reason people buy. Then price is your position and moving it moves the business.
When your service is currently poor. A price rise into a period of complaints converts a service problem into a churn problem, and fixing it afterwards costs more than the increase was worth.
And when you cannot say what the customer gets for it. Not because they will necessarily ask, but because if you cannot answer it, you will discount at the first hint of resistance and end up worse off than before.
What this leaves out
- Assumes variable cost per unit stays flat as volume changes. At significantly lower volume some costs behave differently.
- Excludes competitive response, which is real in commoditised markets and irrelevant in most small service businesses.
- Uses contribution rather than gross profit, so fixed costs are unaffected by either change, which is what makes the comparison clean.
This arithmetic is free to run in your browser — no signup, nothing held back.
Open the free calculatorCommon questions
- How much can I raise prices without losing customers?
- The arithmetic tells you how much you can afford to lose, which is the more useful question. At a 5% rise on a 56% contribution margin you can lose 8% of volume and be no worse off, and in practice most businesses lose far less than that.
- Should I raise prices for existing customers too?
- Eventually, with notice. Holding old customers at old prices forever means your best relationships fund your worst margins, and the gap only widens.
- What if a competitor undercuts me?
- Check whether they are actually cheaper on the same thing before responding, because they usually are not. If they are, matching them on price means competing on the one dimension where the lower cost base always wins.
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The formulas above, already built and checked — so you fill in your numbers rather than the arithmetic.
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Last reviewed 22 August 2026