About
About OneStop Calculators
Accurate, transparent, and privacy-first calculators for finance, health, and everyday life.
OneStop Calculators was created with a simple goal: give people fast, trustworthy answers to the financial and health questions they face every day — without requiring sign-ups, selling data, or hiding the maths behind black boxes.
Whether you need to estimate your Indian salary in-hand after PF and income tax, project a UK student loan repayment timeline, calculate your US paycheck with state-level withholding, or just check your Body Mass Index, we want the answer to be one search away.
Our principles
Accuracy first
Every calculator is built from published formulas and verified against known test cases. We cite the formulas we use — like the Mifflin–St Jeor equation for BMR or India's Payment of Gratuity Act — so you can check our work.
Privacy by design
All calculations run entirely in your browser. Your salary, weight, loan amount, and every other input stays on your device. We do not collect, transmit, or store personal data.
Transparency
Each calculator page explains what the tool does, the formula behind it, a worked example with real numbers, how to interpret results, and honest notes about limitations. No vague promises — just clear maths.
Free to use
Every calculator on the site is free, with no premium tiers, no feature gates, and no login walls. We sustain the project through unobtrusive advertising, not by charging users.
Accessible design
We build with semantic HTML, keyboard navigability, and responsive layouts so the tools work well on phones, tablets, and desktops — and for users who rely on assistive technology.
Regularly updated
Tax thresholds change, interest rate benchmarks shift, and health guidelines evolve. We update our calculators when official figures are revised so you are working with current data.
What we cover
- India — Salary in-hand, GST, PF contributions, gratuity, EMI planners (home, car, personal, credit card), fixed deposit and recurring deposit projections, credit card interest estimates, and loan comparison tools.
- United Kingdom — PAYE income tax, National Insurance, student loan repayments (Plan 1, Plan 2, and comparison), salary breakdowns, and PAYE vs self-employed comparisons.
- United States — Federal and state withholding for all 50 states, paycheck calculators, take-home pay estimators, and overtime pay calculators compliant with FLSA rules.
- Global & utilities — Compound interest, simple interest, savings goals, debt payoff timelines, emergency fund planning, inflation adjustment, percentage calculations, bill splitting, and unit converters for length, weight, temperature, area, speed, and currency.
- Health — BMI, BMR, calorie needs (TDEE), ideal weight ranges, and daily water intake guidelines.
Disclaimer
The calculators and content on this site are for informational and educational purposes only. They are not financial, tax, legal, or medical advice. Results are based on simplified formulas and may not reflect every individual circumstance. Always consult a qualified professional — an accountant, financial adviser, doctor, or solicitor — before making decisions based on calculator output. Read our full terms and conditions for details.
Get in touch
Have a question, found an error, or want to suggest a new calculator? We would love to hear from you. Visit our contact page or email us at onestopcalculators@gmail.com. We also welcome guest contributions — learn more on our Write for us page.