Price Comparison Calculator
The Price Comparison Calculator computes price comparison from the relation saving percent = (dearer unit price - cheaper unit price) / dearer unit price x 100. It takes 4 inputs (price of product a in $, size or quantity of product a in units, price of product b in $, size or quantity of product b in units) and returns the price comparison. These calculators are for people working through everyday money questions: judging whether a price or an offer is worth taking, working out who owes what on a shared bill or cost, and comparing what one borrowing option costs against another, so the number feeds a concrete decision about spending, splitting or borrowing. Enter your values below and the result updates instantly, and you can share a permalink that pre-fills the exact calculation. Enter every amount in the same currency, and where a calculator uses a rate or a period, keep those on one consistent basis (monthly figures with monthly, annual with annual); be clear about whether each amount is before or after tax and fees, and round only the final figure rather than rounding at each step. For example, with price of product a = 2 $, size or quantity of product a = 100 units, price of product b = 4 $, size or quantity of product b = 100 units, the price comparison works out to 50, and the worked example further down the page shows every step so you can follow the arithmetic and reproduce it by hand. The method is the standard form documented by CalculatorHub methodology, and the figure above each result carries the date it was last verified. The result is arithmetic on the amounts you type in, so what you actually pay or receive can differ once a seller's or lender's own rounding, fees, minimum charges and contract terms apply; use it as a working figure for your own planning and check it against the offer, statement or agreement in front of you.
With Price of product A = 2 $, Size or quantity of product A = 100 units, Price of product B = 4 $, Size or quantity of product B = 100 units, the result is 50.
Applies to: any numeric inputs. Method source: CalculatorHub methodology, checked 2026-06-23.
The formula
saving percent = (dearer unit price - cheaper unit price) / dearer unit price x 100
Worked example
With Price of product A = 2 $, Size or quantity of product A = 100 units, Price of product B = 4 $, Size or quantity of product B = 100 units:
- Unit price A = 0.020000
- Unit price B = 0.040000
- Saving of cheaper option = 50.00 percent
- Price Comparison = 50
This worked example is one of the automated golden-value tests this calculator must pass before it can publish.
What this assumes
- Inputs are real numbers in the units shown.
- The result is the exact value of saving percent = (dearer unit price - cheaper unit price) / dearer unit price x 100; general information, not professional advice.
Frequently asked questions
What formula does this use?
saving percent = (dearer unit price - cheaper unit price) / dearer unit price x 100, the standard form documented by CalculatorHub methodology.
Does the result ever change over time?
No. This is a pure formula with no external rate, so the same inputs always give the same result.
Official sources and verification
- Method: CalculatorHub methodology, checked 2026-06-23.
Reviewed by the CalculatorHub team, edited by James Graham, 2026-06-23. See our methodology. General information, not professional advice.