Calculator Guides
Deep-dive guides explaining the formulas, concepts, and real-world applications behind all 61 of our calculators. Every calculator has its own guide.
Financial
(24 guides)EMI Calculator Guide
What is EMI, the formula, and how to reduce monthly payments.
Loan Calculator Guide
Monthly payments, total interest, and amortisation explained.
Compound Interest Explained
The formula, Rule of 72, and the power of compounding.
SIP Calculator Guide
How SIPs work, the formula, and long-term wealth building.
ROI Calculator Guide
Return on investment formula, annualised ROI, and benchmarks.
How GST is Calculated
GST slabs, CGST vs SGST vs IGST, and adding/removing GST.
Tax Calculator Guide
India income tax slabs, old vs new regime, deductions.
Currency Conversion Guide
Exchange rates, how to convert currencies, best rate tips.
Salary Calculator Guide
CTC vs take-home pay, PF, HRA, and all salary deductions.
Discount Calculator Guide
Percentage discounts, original price recovery, double discounts.
Home Loan EMI Calculator
Monthly EMI, total interest and tax benefits on a home loan.
Car Loan EMI Calculator
EMI from on-road price and down payment, plus total cost.
Personal Loan EMI Calculator
EMI and true cost including processing fee and GST.
SIP Calculator for ₹5,000 per Month
What a ₹5,000 monthly SIP grows to in 5–30 years.
GST on Restaurant Bill Calculator
5% or 18%? Check the GST and service charge on a bill.
FD Calculator
Fixed deposit maturity with quarterly compounding and TDS.
PPF Calculator
Tax-free PPF maturity at the current 7.1% rate.
HRA Exemption Calculator
Tax-free HRA under the old regime, with the 2026 metro list.
Mortgage Calculator
Monthly payment with taxes, insurance, PMI and HOA.
Mortgage Extra Payment Calculator
How much interest and time extra payments save.
Auto Loan Calculator
Car payment with trade-in, sales tax and fees.
Salary to Hourly Calculator
Convert annual salary to hourly, weekly and monthly pay.
Tip Calculator
Tip amount and split bill per person, with a tipping guide.
Sales Tax Calculator
Add sales tax to a price or find the pre-tax amount.
Math
(9 guides)Percentage Calculator Guide
All percentage formulas — X% of Y, increase, decrease, difference.
Scientific Calculator Guide
Logs, trig, order of operations, and all scientific functions.
Age Calculator Guide
Exact age in years, months, and days — and cultural age systems.
Average Calculator Guide
Mean, median, mode, and range — when to use each.
Ratio Calculator Guide
Proportions, cross-multiplication, and real-world ratio applications.
Fraction Calculator Guide
Add, subtract, multiply, divide fractions — with LCD and simplification.
Quadratic Formula Guide
The formula, discriminant, real vs complex roots, and factoring.
Speed Distance Time Guide
SDT triangle, formulas, unit conversions, and average speed.
Power & Root Calculator Guide
Exponent laws, nth roots, negative and fractional exponents.
Conversion
(7 guides)Length Converter Guide
Metres, feet, inches, km, miles — full reference table.
Weight Converter Guide
kg, lbs, grams, ounces, stone — with US vs UK differences.
Temperature Converter Guide
°C, °F, and Kelvin — formulas and key reference temperatures.
Area Converter Guide
Square metres, sq ft, acres, hectares — land area conversions.
Volume Converter Guide
Litres, gallons, cups, fl oz — US vs UK volume units explained.
Data Storage Guide
Bits, bytes, KB, MB, GB, TB — binary vs decimal and why drives show less.
Time Converter Guide
Seconds, minutes, hours, days, weeks, months, years — full table.
Metal & Material
(5 guides)Gold Calculator Guide
Karats, purity, price per gram, troy ounces, and making charges.
Silver Calculator Guide
Sterling silver 925, purity grades, and how to value silver.
Steel Weight Calculator Guide
Weight formulas for flat bars, round bars, and steel sheets.
Metal Weight Calculator Guide
Density of aluminium, copper, brass, titanium — weight formulas.
Copper Calculator Guide
Scrap grades, LME pricing, and how to calculate copper value.
Health
(6 guides)BMI Formula Explained
BMI formula, categories, limitations, and better health metrics.
Calorie Calculator Guide
TDEE, BMR, Mifflin-St Jeor formula, and calorie goals for weight loss.
Water Intake Calculator Guide
Daily hydration formula, signs of dehydration, and the 8-glasses myth.
Body Fat Calculator Guide
US Navy method, healthy body fat ranges, and measurement accuracy.
Pregnancy Calculator Guide
Due date calculation, gestational weeks, and trimester breakdown.
Heart Rate Zones Guide
Max heart rate, 5 training zones, fat burning, and resting HR.
Business
(6 guides)Profit Margin Guide
Gross margin, net margin, industry benchmarks, and how to improve margins.
Break-Even Analysis Guide
Break-even units, revenue, contribution margin, and fixed vs variable costs.
Markup Calculator Guide
Markup vs margin, selling price from cost, and markup by industry.
Commission Calculator Guide
Sales commission, tiered structures, real estate, and affiliate commissions.
Invoice Calculator Guide
Invoice structure, GST calculation, CGST vs IGST, and record-keeping.
E-Commerce Calculator Guide
Net profit after platform fees, ROAS, break-even, and CAC explained.
All 61 Calculators, All Explained
Every calculator on this site has a dedicated guide covering the formula, worked examples, and FAQs.
Browse All Calculators