CalcMaster Blog
Plain-English guides to every calculator: what the formula is, when to use it, and the mistakes that cost real money.
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The complete guide to finance calculators (24 tools, one page)
A plain-English tour of every finance calculator on CalcMaster: what each one solves, the formula behind it, and when it actually moves the needle in your portfolio.
12 math calculators that quietly replace a textbook
From basic arithmetic to matrix determinants, here's every math calculator on CalcMaster and the kind of problem each one is designed to vanish.
8 health calculators that turn vague advice into real numbers
BMI, BMR, calories, body fat, water intake — what each calculator measures, the formula it uses, and how to interpret the result without obsessing over it.
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Unit converters that actually live up to the name
10 unit converters — length, mass, temperature, area, volume, speed, time, data, energy, pressure — built around a single consistent UX.
5 date & time calculators for everything calendars get wrong
Age, date difference, date arithmetic, working days, and time zones — the date calculations a phone calendar app refuses to do.
Crypto & stock calculators that keep you honest about returns
Six tools — crypto profit, staking yield, DCA, stock averaging, P/E ratio, position size — that turn vibes into spreadsheets.
EMI calculator: the only loan number you actually need
How the EMI formula works, what 'reducing balance' means, and why your total interest is often more than the principal you borrowed.
SIP calculator: the ₹5,000/month case for not panicking
How a SIP grows, the formula your fund house won't show you, and the simple arithmetic that turns a modest monthly amount into a meaningful corpus.
BMI calculator: a quick number with very real limits
How BMI is computed, what the categories really mean, and why one number can't capture body composition — yet still gets used everywhere.
Mortgage calculator: the 30-year decision in 30 seconds
Why mortgage isn't just "loan with a house attached", how amortization actually works, and the prepayment scenarios that quietly save lakhs.
Currency converter: live rates, no signup, no surprises
How a currency converter actually works, the difference between mid-market rate and the rate your bank gives you, and why every conversion costs more than the math says.
Age calculator: precise to the day, useful beyond birthdays
Why "how old are you" is harder than it looks, how the calculator handles leap years, and the surprisingly common use cases that aren't birthdays.
Discount calculator: what "70% off + extra 20% off" actually means
Stacked discounts, GST inclusion, MRP vs final price — the math behind the price tags retailers hope you don't compute.
GST calculator: inclusive ↔ exclusive in both directions
How to add GST, how to back-it-out, why "GST extra" and "GST inclusive" make different math, and the slabs that matter for everyday purchases.
Percentage calculator: the four operations you keep mixing up
% of, % change, add %, subtract % — all four modes, the formulas behind them, and the moments each one actually applies.
Compound interest calculator: the formula that runs the world
The math behind the eighth wonder of the world — how compounding works, why frequency matters, and the rule of 72 that estimates everything in your head.
SIP vs lumpsum — which actually wins (with math, not vibes)
If you have ₹12 lakh today, should you put it in all at once or spread it over 12 months as a SIP? The data, the math, and the right answer for your situation.
Step-up SIP vs flat SIP — the 10% raise that doubles your corpus
Increasing your SIP by 10% every year (when you get a raise) can grow your retirement corpus by 60–100%. The math is brutal and the implementation is one form.
SIP vs prepaying a loan — the math, the tax, the right call
You have ₹50k extra each month. Should it go into an equity SIP or against your home-loan EMI? The answer depends on rates, taxes, and your risk appetite.
SIP tax: what India actually charges on your mutual-fund gains
STCG, LTCG, the ₹1 lakh exemption, ELSS, dividend tax — everything you need to know about tax on SIP returns, in one place.
Goal-based SIP — reverse-engineer the number from the dream
Don't pick an arbitrary monthly amount. Work backwards from the goal — house down-payment, kid's college, retirement corpus — and let the math tell you the SIP.
10 SIP mistakes that cost real money (and how to avoid them)
Stopping during a crash, chasing last year's winner, not stepping up, ignoring expense ratios — the ten common SIP errors, ranked by how much they cost you.