About CalcTower

CalcTower is a set of focused calculators, each built to answer one question clearly. There is no sign-up, no paywall, and no limit on how much you use them.

Every calculation runs in your browser. Nothing you type is sent to a server, which means results appear instantly and the numbers you enter stay on your device.

CalcTower currently offers 110 calculators organised into 13 categories:

• Math Calculators — fractions, averages, medians, ratios, prime numbers, GCF and LCM.
• Percentage Calculators — percentage of a number, increase, decrease, change, and difference.
• Student Calculators — GPA, weighted grades, exam scores, attendance, and required final grades.
• Finance Calculators — compound and simple interest, loans, mortgages, debt payoff, and savings.
• Business Calculators — hourly and freelance rates, commission, revenue, profit, break-even, and ROI.
• Time & Date Calculators — age, date differences, durations, countdowns, and date arithmetic.
• Measurement & Conversion — length, weight, temperature, volume, area, speed, and data storage.
• Fashion & Size Calculators — clothing, shoe, ring, bra, and jeans sizing across regions.
• Beauty & Makeup Tools — foundation and makeup shade matching, and beauty measurements.
• Creator & Influencer Tools — engagement rates and sponsorship rate estimates.
• Productivity Calculators — time cards, work hours, overtime, and Pomodoro planning.
• Home & Apartment Calculators — paint, flooring, tile, room area and volume, and utility costs.
• Color & Design Tools — HEX/RGB/HSL conversion, WCAG contrast, palettes, and CSS units.

You can browse everything from the full calculator directory or start from a category.

Each calculator documents the formula it uses, so you can check the method rather than trusting a number blindly. Where a tool has to make an assumption — a standard number of working weeks, a typical paint coverage rate, a particular grading scale — we try to say so on the page.

We also try to be honest about limits. Calculators give informational estimates, and for decisions with real consequences they are not a substitute for a qualified professional. Our Disclaimer explains that in more detail.

If you spot a result that looks wrong, we would rather hear about it than not — the Contact page explains what makes a report easy to act on.

CalcTower runs no third-party analytics, no advertising networks, and no tracking pixels. The only things stored in your browser are your theme preference, your favourites, and your recently used calculators. The Privacy Policy sets out the specifics.