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Calculator Guides

Clear explanations and worked examples for EMI, SIP, salary, GST, BMI and more, with free calculators.

Calculator Guides · 6 min read

How to Calculate a Mortgage Payment (PITI) — With Example

The formula behind your monthly mortgage payment, what PITI means, and a worked $400k example.

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Calculator Guides · 5 min read

How to Calculate a Car Payment — With Tax & Trade-In

How the amount financed and monthly car payment are worked out — tax and trade-in included.

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Calculator Guides · 6 min read

How a 401(k) Employer Match Works — And Why It Matters

What '50% up to 6%' really means, how to capture the full match, and how it compounds over a career.

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Calculator Guides · 5 min read

How to Pay Off Credit Card Debt Faster — The Math

Why minimum payments trap you, and how a bigger payment cuts both the time and the interest.

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Calculator Guides · 4 min read

How to Calculate Sales Tax: Add & Remove It — Formula

How to add sales tax to a price and how to reverse it out of a total — with formulas and examples.

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Calculator Guides · 4 min read

How to Calculate the Days Between Two Dates

Count days between two dates accurately — including the inclusive/exclusive trap and how to count only working days.

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Calculator Guides · 4 min read

How to Convert Units: Length, Weight & Temperature

The conversion factors that actually matter — cm↔in, kg↔lb, °C↔°F — with worked examples and a free converter.

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Calculator Guides · 3 min read

How to Count Words and Characters (Free, No Upload)

Count words, characters, sentences and reading time — and hit strict limits with confidence — free and private in your browser.

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Calculator Guides · 3 min read

How to Calculate a Tip and Split the Bill (Quick Guide)

Fast mental math for a 15/18/20% tip, splitting the bill evenly, and the tip-on-tax question answered.

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Calculator Guides · 4 min read

How to Calculate Your Exact Age (Years, Months & Days)

The manual method for an exact age in years, months and days — plus the leap-year trap most people miss.

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Calculator Guides · 5 min read

How to Read a Loan Amortization Schedule (With Example)

How each loan payment splits into interest and principal, why prepaying early saves the most, and the true total cost.

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Calculator Guides · 4 min read

How to Calculate a Discount and Sale Price (With Examples)

The discount and sale-price formulas, quick mental tricks, stacked discounts, and how to find the percent off.

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Calculator Guides · 6 min read

How to Calculate Your Daily Calorie Needs (BMR & TDEE)

Work out your BMR and TDEE with the Mifflin-St Jeor formula, then set calories for cutting, maintaining or gaining.

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Calculator Guides · 6 min read

How to Calculate In-Hand Salary from CTC (With Example)

Why your CTC and your bank credit differ — the gross-to-net breakdown with a worked example.

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Calculator Guides · 6 min read

How to Calculate Compound Interest (Formula & Example)

The compound interest formula, a worked ₹1-lakh example, and why compounding frequency and time do the heavy lifting.

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Calculator Guides · 5 min read

How to Calculate BMI (Formula, Example & Categories)

The BMI formula in metric and imperial, a worked example, the WHO categories, and where BMI falls short.

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Calculator Guides · 5 min read

How to Calculate GST (Add & Remove) — Formula & Examples

How to add GST to a price and how to back it out of a GST-inclusive amount — with formulas and 18% worked examples.

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Calculator Guides · 5 min read

How to Calculate a Percentage (Formulas & Examples)

The three percentage formulas everyone needs — percent of a number, one number as a percent of another, and percentage change — with worked examples.

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Calculator Guides · 6 min read

How to Calculate EMI (Formula, Example & Free Calculator)

The EMI formula explained, a worked ₹10-lakh loan example, and how rate and tenure change what you really pay.

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Calculator Guides · 6 min read

How to Calculate SIP Returns (With Formula & Example)

The SIP future-value formula, a worked ₹10,000/month example, and why starting early matters.

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