Cost Increase Price Adjustment Calculator

Understanding the cost increase price adjustment calculator — concept and principle

When costs rise, you must decide how much to pass on to customers. This calculator shows two standard answers: the new selling price that keeps your margin percentage unchanged, and the lower new price that only protects the profit you earn per unit in money terms. It works with any currency; the default example uses US dollars.

How it is calculated

Let P be the current price, C the current unit cost and i the cost increase in percent.

• New price, same margin % = C × (1 + i/100) ÷ (C ÷ P). Because the cost-to-price ratio stays the same, this simplifies to P × (1 + i/100).
• Price increase needed for the same margin % = i (the same percentage as the cost increase).
• New price, same profit amount = P + C × i/100, which adds only the extra cost in money terms.

The principle

A margin percentage is a ratio. If cost is 60% of price before the change, keeping the margin means cost must still be 60% of price afterwards, so price and cost must grow by the same factor. Keeping the profit amount is a different goal: you accept a slightly lower margin percentage but your profit per unit in dollars stays exactly where it was.

Worked example

1. Inputs: price $100, cost $60, cost increase 8%.
2. New cost = 60 × 1.08 = $64.80; cost-to-price ratio = 60 ÷ 100 = 0.60.
3. Same margin %: 64.80 ÷ 0.60 = $108.00 (an 8% price increase). Margin stays at 40%.
4. Same profit amount: 100 + 60 × 0.08 = 100 + 4.80 = $104.80. Profit stays $40 per unit, but the margin falls to 40 ÷ 104.80 ≈ 38.2%.

How to read the result

The two prices form a practical range. Below the same-profit price you absorb part of the increase yourself. The higher price (same margin %) keeps your ratios and percentage targets intact, which matters when other costs such as commissions or card fees are charged as a percentage of price. Where you land between the two depends on competition and how sensitive your customers are to price.

Common mistakes

• Raising price by the cost increase percentage applied to the price, then calling it "the same profit" — that is the same-margin result, not the same-profit one.
• Ignoring volume: a higher price may reduce units sold, so total profit can fall even if unit profit is protected.
• Using total cost when only one cost component rose; enter the percentage change of the whole unit cost.

Frequently asked questions

Should I keep the margin percentage or the profit amount?

Keeping the profit amount is the gentler increase for customers and protects your cash profit per unit. Keeping the margin percentage is safer when inflation affects many costs at once or when percentage-based fees grow with price.

How do I find the cost increase percentage?

Divide the new unit cost by the old unit cost, subtract 1 and multiply by 100. For example, cost moving from $60 to $64.80 is an 8% increase.

Sources: Thomas T. Nagle and Georg Müller, The Strategy and Tactics of Pricing (Routledge) · Paul W. Farris et al., Marketing Metrics: The Definitive Guide to Measuring Marketing Performance (Pearson)