Percentage Calculator — Solve Any Percentage Problem Instantly

By sadiqbd · June 6, 2026

Percentages come up constantly, and the mental math rarely sticks

What's 18% of ৳4,750? If the price dropped from ৳2,200 to ৳1,870, what percentage did it fall? You got a raise from ৳55,000 to ৳62,000 — is that a 12% increase or a 13% increase? These questions come up in everyday life more than most people expect, and the mental math is just awkward enough that most people either guess or reach for a calculator app and punch in a half-remembered formula.

The problem with doing it freehand is that percentages have several different forms, and it's easy to confuse them. "What is X% of Y" is a different calculation from "X is what percent of Y" — they look similar but they're not the same operation. A percentage calculator handles all of these cleanly, with no formula-juggling required.

The Three Core Percentage Calculations

Most percentage questions fall into one of three categories. It helps to know which one you're dealing with before you start.

1. Finding a percentage of a number "What is 15% of ৳8,500?" Formula: (percentage ÷ 100) × number = (15 ÷ 100) × 8,500 = ৳1,275

2. Finding what percentage one number is of another "৳1,275 is what percentage of ৳8,500?" Formula: (part ÷ whole) × 100 = (1,275 ÷ 8,500) × 100 = 15%

3. Percentage increase or decrease "A price went from ৳8,500 to ৳9,775. What's the percentage increase?" Formula: ((new − old) ÷ old) × 100 = ((9,775 − 8,500) ÷ 8,500) × 100 = 15% increase

These three cover the vast majority of percentage problems in finance, business, academics, and everyday life. The calculator handles all three — you just pick the one that matches your question.

How to Use the Percentage Calculator on sadiqbd.com

Select the type of calculation — choose whether you're finding a percentage of a number, calculating what percentage one number is of another, or finding the percentage change between two values.
Enter your numbers — fill in the values relevant to your calculation. The input fields adjust based on the type you selected.
Read the result — the answer appears immediately, with no button to press. Change any value and the result updates instantly.

The whole operation takes about 10 seconds. No formula needed, no order-of-operations errors, no accidentally dividing when you should multiply.

Real-World Examples

Calculating a tip or service charge

Your restaurant bill comes to ৳3,600. The service charge is 10% and VAT is 15%. What do you actually owe?

10% of ৳3,600 = ৳360 (service charge)
15% of ৳3,600 = ৳540 (VAT)
Total: ৳3,600 + ৳360 + ৳540 = ৳4,500

Run each percentage separately or add them (25% of ৳3,600 = ৳900) — either way the calculator gets you there in seconds.

Checking a discount

A jacket is marked at ৳5,500 with a 30% discount. What's the sale price?

30% of ৳5,500 = ৳1,650. Sale price = ৳5,500 − ৳1,650 = ৳3,850

Or use the percentage-of calculation: the sale price is 70% of ৳5,500 = ৳3,850. Same answer, different path.

Evaluating an investment return

You invested ৳1,20,000 in a mutual fund. It's now worth ৳1,43,500. What's your return?

Percentage increase = ((1,43,500 − 1,20,000) ÷ 1,20,000) × 100 = 19.58%

That's your gain as a percentage of what you put in — a useful number for comparing against other investment options or benchmark indices.

Academic scoring

A student scored 347 out of 500 in their exams. What percentage did they get?

(347 ÷ 500) × 100 = 69.4%

Their school requires 70% to pass with distinction. They missed it by 0.6% — which is 3 marks. Knowing this precisely (rather than roughly) helps them understand exactly what they need to aim for next time.

Salary hike calculation

An employee's salary goes from ৳48,000 to ৳54,500. What's the percentage increase?

((54,500 − 48,000) ÷ 48,000) × 100 = 13.54%

This is the number worth knowing in a salary negotiation — both to evaluate an offer ("is this 13.5% raise competitive?") and to make a case for one.

Common Percentage Mistakes Worth Knowing

Mixing up the base. Percentage change is always calculated on the original (old) value, not the new one. A price that rises from ৳100 to ৳120 is a 20% increase. But ৳120 dropping to ৳100 is not a 20% decrease — it's a 16.67% decrease, because the base is now ৳120. This asymmetry trips people up constantly.

Adding percentages directly. A 10% discount followed by a 10% tax does not net out to zero. If something costs ৳1,000, a 10% discount gives ৳900, then 10% tax on ৳900 gives ৳990. The two percentages apply to different bases, so they don't cancel.

Confusing percentage points with percentages. If an interest rate goes from 5% to 7%, that's a 2 percentage point increase — but it's a 40% increase in the rate itself ((7−5)÷5 × 100 = 40%). Financial and economic reporting often uses "percentage points" and "percent" interchangeably, which can be misleading.

Reversing the formula when finding the original price. If a price after a 20% discount is ৳800, the original price is NOT ৳800 + 20% = ৳960. It's ৳800 ÷ 0.8 = ৳1,000. The 20% was taken off the original, not the discounted price.

Tips for Using Percentages Confidently

Work with decimals for chained calculations. Instead of calculating 15% of a number and then 8% of that, convert to decimal multipliers: 1.15 × 0.92 = 1.058, meaning the net effect is a 5.8% increase. Chaining decimal multipliers avoids the compounding-base confusion.

Use the percentage change formula for anything that moved. Whether it's stock prices, revenue figures, test scores, or body weight — if a value changed, the percentage change formula ((new−old)÷old × 100) gives you the meaningful number, not just the raw difference.

Sanity-check discounts before buying. When a store advertises "was ৳3,500, now ৳2,800," verify the claimed percentage. (2,800 − 3,500) ÷ 3,500 × 100 = −20%. If they claimed 25% off, something doesn't add up.

For tax-inclusive pricing, divide — don't subtract. If a price includes 15% VAT, the pre-tax amount is price ÷ 1.15, not price × 0.85. These give different answers, and the correct one is the division.

Frequently Asked Questions

What's the difference between percentage and percentage points? A percentage is relative to a base. A percentage point is an absolute difference between two percentages. If your score goes from 60% to 75%, it increased by 15 percentage points and by 25% (15÷60 × 100). The distinction matters in finance, polling, and academic contexts.

How do I find the original price before a discount? Divide the discounted price by (1 − discount rate). For a ৳850 item after a 15% discount: ৳850 ÷ 0.85 = ৳1,000. Don't add the percentage back to the discounted price — that gives the wrong answer.

Can I calculate multiple percentages at once? The calculator handles one calculation at a time, but you can run multiple calculations back to back instantly. For layered percentages (discount then tax), run each one sequentially.

Is percentage increase the same as percentage of? No. "X% of Y" tells you a portion. "Percentage increase from X to Y" tells you how much Y grew relative to X. Different operations, different results.

Is the percentage calculator free? Yes — completely free, no sign-up, works instantly on any device.

Percentages are everywhere: on price tags, in bank statements, on report cards, in business reports, in health metrics. Getting comfortable with the three core operations — find a percentage, find what percentage, find the change — handles almost every real-world situation. The calculator makes all three immediate.

Try the Percentage Calculator free at sadiqbd.com — no formula needed, just your numbers.