Why This Site Exists
A lot of money decisions come down to a calculation that usually happens out of sight: what the monthly payment will be, how much a 401(k) might grow by the time you're 65, what a raise actually adds to a paycheck after taxes. Digital Calculator lets you run those numbers yourself and see how the answer was worked out.
Some of the calculators are for big decisions, like comparing two mortgage offers or choosing when to claim Social Security. Others answer quick everyday questions, like how to split a dinner bill.
Who Builds This
Digital Calculator is built and maintained by Mark, a senior software engineer and tech lead in the financial services industry, through Markco Labs LLC. Mark designs each calculator, reviews how it reaches its answer, and is the person who fixes it when something is wrong.
The site covers fewer topics than the big calculator aggregators, and that's intentional. It's easier to keep 40 calculators correct than several hundred. Each one is tied to primary sources, such as IRS publications and Social Security Administration rules, and gets updated when those rules change.
You also don't have to take our word for any result. Every calculator explains the formula behind it, so you can check the math yourself.
How the Calculators Work
Free, with nothing to sign up for
Every calculator is free to use. There's no account to create and no email address to hand over. Enter your numbers and you get the result right away.
Your numbers stay in your browser
The calculations run on your own device. The figures you enter or import stay on your device and aren't sent to our servers. If you choose to share a summary with an AI assistant, it goes to that assistant's provider under its own privacy terms, not to us. Our calculator API for AI assistants is a separate service that processes the values sent to it; our privacy policy explains what it keeps. If you allow analytics, we collect anonymous usage data, such as which pages get visited, so we can tell what's working. It never includes the numbers you enter.
No ads
The site doesn't show ads, and no calculator nudges you toward a particular lender or product.
The Calculators
There are 40 calculators, grouped by topic. Pick a group to see what's in it, or browse the full list.
How We Check the Math
The formulas are published
Every calculator explains the formula it uses, either on the page itself or on a linked methodology page with worked examples. The mortgage methodology is a good place to see what that looks like.
Automated tests
More than 10,000 automated tests check the calculations, from everyday inputs to edge cases and boundary values. Some compare results against saved reference answers, so an unexpected change in any output gets caught.
Checked against primary sources
Tax figures are checked against IRS publications, benefit estimates against Social Security Administration rules, and loan math against the standard formulas banks and lenders use. We cite the original source, not another website.
Updated when the rules change
When contribution limits, tax brackets or other published figures change, the affected calculators and articles are updated and their "last updated" date moves with them. A page's date only changes when its content does.
Accessibility
We build to the WCAG 2.1 AA standard and use automated accessibility scans to check for problems like low color contrast, missing form labels and out-of-order headings. A full manual audit with assistive technology hasn't been done yet. The Trust & Compliance page lists what has and hasn't been checked.
Corrections
If a result looks wrong, email admin@markcolabs.com with the calculator and the numbers you entered. We'll check it against the source, fix it if we got it wrong, and update the page's date.
For more detail, including which tests run and where each tax and benefit figure comes from, see Trust & Compliance.
About Markco Labs
DigitalCalculator.info is owned and operated by Markco Labs LLC, a small software company that builds practical tools for everyday use.
Markco Labs launched Digital Calculator in 2025 because the calculators we wanted didn't exist. Most of the ones we tried were slow, covered in ads, or gave an answer without showing how they got it.
How This Site Makes Money
The calculators on this site are free. They're paid for by products we sell to businesses:
- Embeddable calculator widgets for other websites
- A calculator API that AI assistants can use
- White-label calculator suites and branded PDF reports
That money doesn't come from ads, affiliate links to lenders, or selling user data. No consumer calculator sits behind a paywall either. If that changes, this page will say so.
Contact Us
Email admin@markcolabs.com with questions, bug reports or ideas for a new calculator.
The Privacy Policy explains what data the site collects, and the Terms of Use cover how you can use it.
Important Disclaimer
The calculators and articles on DigitalCalculator.info are for general information and education only. They aren't financial, legal or tax advice.
Results are estimates. They depend on the numbers you enter and the assumptions each calculator makes, and your actual results may be different.
Before a major financial decision, talk to a qualified professional such as a financial advisor, accountant or attorney.