About MyPctCalculator
A free suite of percentage calculators built for everyday math -- tips, discounts, grades, margins, and more. No signup. No paywalls. No ads blocking the tool.
Percentage calculations come up constantly -- at a restaurant, at checkout, at work, in school. Yet finding a clean, fast calculator online usually meant fighting past ads that covered the tool itself, navigating confusing interfaces designed to keep you scrolling, or getting a raw number with no explanation of how it was calculated.
We built MyPctCalculator to fix that: get your answer instantly, see the formula, and move on.
9
Free calculators
55+
In-depth guides
0
Signups required
What makes it different
Built differently, on purpose
Shows the formula
Every calculator displays the underlying formula alongside the result. You see how the answer was calculated, not just what it is.
Works on mobile
Inputs are sized for fingers, not mouse cursors. Results are readable without zooming. No horizontal scrolling.
No signup required
There is no account, no email, no cookies notice beyond the legal minimum. Open a page, use the tool, done.
Educational content
Each calculator page includes a plain-English explanation of the math, real-world examples, and answers to common questions.
Fast and lightweight
The site loads quickly on any connection. No heavy frameworks, no unnecessary scripts running in the background.
Constantly improving
We refine the calculators based on real usage -- adding features like bill splitting, reverse calculations, and clearer result formats.
The calculators
Nine dedicated tools
Each built for a specific percentage problem rather than trying to do everything in one cluttered interface.
Tip Calculator
Calculate tips and split bills by the number of people.
Discount Calculator
Find the sale price and your exact savings on any discount.
Sales Tax Calculator
Calculate tax on any purchase and find pre-tax prices.
Grade Calculator
Convert scores to percentages and letter grades.
Percentage Change
Measure how much a value increased or decreased over time.
Percentage Difference
Compare two values side by side without a defined starting point.
Margin Calculator
Calculate gross profit margin and find the right selling price.
What Percent?
Find what percentage one number is of another.
Salary Increase
Work out a raise as a percentage, or a new salary from one.
Behind the site
Who's behind it
MyPctCalculator is designed and maintained by De Van Do, an independent developer with a background in technology. What started as curiosity about building tools for financial literacy grew into a small network of free calculator sites covering percentages, insurance estimates, loans, and taxes.
We don't believe utility websites should be aggressive about monetization at the expense of the user experience. That means no pop-ups, no mandatory accounts, no ads placed over the calculator itself, and no dark patterns designed to get you to click on something you didn't mean to.
The site is supported by non-intrusive display advertising below and around the content -- not blocking it. If you find the tools useful and want to support the site, just using it and sharing it with someone who needs it is enough.
Our commitment
Our trust promise
Your data never leaves your browser
Every calculation runs locally in JavaScript on your device. We have no server receiving your numbers, no database storing your inputs.
We update for accuracy
Tax rates, tipping norms, and financial benchmarks change. When they do, we update both the calculators and the accompanying guides.
Transparent about limits
These calculators are educational tools for quick estimates, not substitutes for professional financial, tax, or legal advice.
No dark patterns
No email gates, no required signups, no paywalls, no ads placed over the calculator itself. The tools are and will remain free.
Methodology
How the calculations work
Every formula on this site uses standard, peer-reviewed mathematical definitions -- the same ones taught in schools and used in financial reporting.
Percentage change
Uses the formula (New -- Old) / |Old| x 100, consistent with the definition used by the U.S. Bureau of Labor Statistics.
Gross margin
Follows the formula (Revenue -- Cost) / Revenue x 100, consistent with GAAP income statement standards.
Sales tax
Uses flat-rate multiplication (Price x Tax Rate), reflecting how most US jurisdictions apply tax at point of sale.
Tip calculation
Tip is calculated on the pre-tax subtotal by default, which is the etiquette standard in the US.
Rounding
We do not round intermediate steps -- only final displayed results -- to minimize accumulated floating-point error.
What's coming
We're continuously adding content to help people understand the math behind each calculation -- not just the result. The blog covers real-world applications of percentage math, from how compound interest works to how to read a nutrition label.
Future tools will expand into more specialized finance calculators, with the same philosophy: free, clean, and educational.