About CalculatePercentageIncrease.com
Who builds and checks the percentage increase calculator, where its formulas come from, and how to report a wrong result.
What this site does
The site has one job: work out percentage increases quickly and show the math. The calculator handles four related questions: the percent change between two numbers, a number after a percent increase, the original value before an increase, and the average yearly increase over several years. It also takes a whole list of number pairs at once and exports the results as CSV.
Who built it
CalculatePercentageIncrease.com was created by Cedrick Reese, founder of ReadyUtilities.com, a retired veteran and web developer who enjoys building free, user-friendly online tools that simplify everyday tasks. My journey began in the early 2000s with affiliate marketing and niche site development, which grew into a passion for creating practical digital utilities and calculators. After retiring, I earned a Computer Systems Technician certificate from UEI College, completed Electro-Mechanical Technologies at Tulsa Welding School, and finished the Carpentry program at Florida State College at Jacksonville. Today, I combine my technical background and craftsmanship by building furniture using traditional woodworking methods, gardening, and developing helpful online tools for users worldwide. It's one of the tool sites I run under Ready Utilities.
Corrections
If a result looks wrong, send the numbers you entered through the contact page. I'll check it against the formula and fix the calculator or the wording if it's off.
The calculator runs entirely in your browser. Its formulas come from the sources listed at the bottom of the calculator page, including Microsoft's own Excel guidance for percent change, and I re-run a set of known answers every time the page changes. When a reader reports a mistake, the fix and a new test case for it go in together, so the same error can't come back.