FREE CALCULATORS · NO SIGNUP · NO ADS
32 calculators built by hand. Free forever.
Calculus, statistics, algebra, finance, physics, chemistry. Each one shows the working steps, not just the answer. I built these because I taught math for years and got tired of opaque online tools.
32Calculators
9Categories
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The three calculators most people open first
Compound Interest Calculator
Where most personal finance learning starts. See how monthly vs daily compounding actually changes the outcome over 30 years.
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Linear Regression Calculator
Best-fit line plus R², residuals and a scatter plot. The one I use whenever someone sends me a spreadsheet asking what the trend is.
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Definite Integral Solver
Step-by-step working for ∫ₐᵇ f(x) dx. The math behind every other calculator on this page.
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Calculus (13)
Limits, derivatives, integrals, series. The kind of math you actually need at exam time and in graduate research.
Definite Integral SolverEvaluate definite integrals with steps.
Inverse Function CalculatorFind f⁻¹(x) for any function you throw at it.
L’Hôpital’s Rule CalculatorResolve 0/0 and ∞/∞ indeterminate forms.
P-Series Test CalculatorConvergence test for Σ 1/nᵖ.
Partial Derivative CalculatorDifferentiate functions of multiple variables.
Partial Fraction DecompositionBreak rational functions into simpler fractions.
Radius of Convergence CalculatorFind R and the interval of convergence.
Riemann Sum CalculatorLeft, right, midpoint sums with grid output.
Taylor Series CalculatorExpand any function around a point.
Mean Value TheoremFind c where f′(c) equals the average rate.
Intermediate Value TheoremVerify roots and continuity guarantees.
Rolle’s Theorem CalculatorFind c where f′(c) = 0 between equal endpoints.
Volume of RevolutionDisk and shell methods, full working steps.
Statistics (4)
Hypothesis testing, regression, intervals. Pass your stats course and ship better A/B tests.
Algebra (5)
Foundational algebra tools that show their work. Useful from school through engineering reviews.
Arc Length CalculatorLength of any curve over an interval.
Difference Quotient Calculator[f(x+h)−f(x)]/h for any function.
Reciprocal of a FractionFlip any fraction in one click.
Standard Form CalculatorConvert numbers to and from scientific notation.
Eigenvalue CalculatorEigenvalues and eigenvectors of any square matrix.
Finance (2)
Compound interest and SIP returns done right. Built after I got tired of misleading bank calculators.
Physics (2)
Mechanics calculators built for physics 101 students who want answers AND the steps.
Chemistry (2)
Pre-balanced chemistry tools. Skip the textbook-only solutions, get the working.
Conversions (2)
The two unit conversions I use the most. Tested against NIST reference values.
Study & Productivity (2)
Two student-focused tools that came out of a decade teaching IIT-JEE and B.Ed math.
Why these calculators look different
Built by an educator
Three years teaching IIT-JEE math, plus a B.Ed in mathematics. Every calculator shows the working steps the way a teacher would on a whiteboard.
No ads, no signup
Run any calculator unlimited times without an account. The page loads in under a second on a 3G connection because there is nothing here trying to track you.
Tested at scale
I use these on my own consulting work and in 10 years of online tutoring. Every formula is benchmarked against textbook reference values and NIST data where applicable.
FAQ
Common questions
Do I need to sign up to use any of these calculators?
No. Every calculator on this page works without an account, without a paywall, and without an email opt-in. Some advanced features may save your inputs to localStorage but nothing leaves your browser.
How accurate are the results?
Each calculator is benchmarked against textbook reference solutions and, where applicable, NIST or government published values. The math itself is exact within JavaScript’s double-precision floating point. For research-grade work, treat the result as the starting point and verify with a CAS.
Can I embed these calculators on my own site?
Not yet. I am building a hosted-widget version for premium subscribers. If you need it sooner, email me with the use case and I can usually package it within a week.
Why no advertising?
Because ads slow the page down and most calculator sites are unusable on mobile. The site stays free thanks to a small set of paid courses, books, and consulting clients listed under Services.
Can you build a calculator I need?
Yes. I take requests when they would help more than one person. Use the suggest-a-calculator link below or email hi@gauravtiwari.org with the topic and a sample input/output.
Are the formulas explained anywhere?
Each calculator page links to a written explainer with the derivation, edge cases, and worked examples. The aim is that you finish the page knowing why the answer is what it is, not just what it is.
THE FRIDAY DROP
One short email every Friday. New calculators, new explainers, what I shipped that week.
Around 4,000 students, freelancers, and self-taught engineers read it. No spam, easy unsubscribe.
Missing a calculator you need?
Tell me what you wanted to calculate today and could not. If it would help more than one person, I will build it within the week and reply with the link.
Email me your idea →