Percentage calculator guide — increase & discount | Itqan

Need to calculate 20% off a product price, a raise after inflation, or a 15% tip? The percentage calculator on Itqan computes increase, decrease, and discount instantly with optional currency. This guide explains calculation types, four everyday scenarios with step-by-step math, a pre-use checklist, and quick shortcuts — written for our users.

What is the percentage calculator?

A digital tool that applies a percentage to an original value and shows the final amount and change — no manual formulas. Enter amount and rate, get instant results.

The tool labels each output clearly: final value, change amount, and original value. Pick a currency symbol for formatted reports or screenshots.

Different from the VAT calculator built for country tax rates — here you set any percentage for any purpose (discount, raise, tip, markup).

When do you need it?

• Shopping: Price after a “30% off” sale.
• Restaurants: Tip or service charge as a percent of the bill.
• Payroll: Annual 5% salary raise.
• Investing: Gain or loss as percent of capital.
• School: Exam score as percent of total marks.
• Business: Margin or client discount on a quote.
• Pricing: Mark up wholesale cost to a retail shelf price.

Whenever you know the original and the rate but not the final figure, the calculator saves mental math.

Calculation types

Increase

Adds a percent to the original. Formula: change = original × rate ÷ 100; final = original + change.

Example: 5,000 + 10% → change = 500 → final = 5,500. Use for raises, tips, tax added on top, or retail markup.

Decrease

Subtracts a percent from the original. Formula: change = original × rate ÷ 100; final = original − change.

Example: 200 − 15% → change = 30 → final = 170. Use when a price drops, a budget is cut, or stock loses value.

Discount

Same math as decrease, wording suited for retail — output is what you pay after discount. The tool shows “after discount” and “discount amount” instead of generic decrease labels.

Example: 400 with 25% off → you pay 300 and save 100.

Real-world scenarios — four common cases

Store discount during a sale

A laptop is tagged at 4,500 SAR with a 30% off weekend promo. Open Percentage calculator, choose Discount, enter 4500 and 30, select SAR, and click Result.

Manual check: 4,500 × 30 ÷ 100 = 1,350 discount → you pay 4,500 − 1,350 = 3,150 SAR. You saved 1,350 — about one-third of the list price. Tap the 10% discount quick button when testing smaller promos without retyping the rate.

Salary raise at year-end review

Your monthly salary is 12,000 SAR and HR confirms a 6% increase. Choose Increase, enter 12000 and 6, currency SAR.

Math: 12,000 × 6 ÷ 100 = 720 → new salary = 12,720 SAR per month. Over twelve months that is 8,640 SAR extra — handy when comparing offers with different raise percentages.

Tip calculation after dinner

The bill is 285 AED and you want to leave 15% tip. Choose Increase (tip is added on top of the bill), enter 285 and 15, pick AED — or tap the 15% tip shortcut which sets increase mode and 15% automatically.

Tip: 285 × 15 ÷ 100 = 42.75 → total = 327.75 AED. Split four ways ≈ 81.94 AED each.

Price markup from wholesale to retail

You buy inventory at 75 USD per unit and target a 40% markup for retail. Choose Increase, enter 75 and 40, currency USD.

Markup: 75 × 40 ÷ 100 = 30 → shelf price = 105 USD. Markup ≠ margin: 30 profit on 105 revenue ≈ 28.6% margin.

How to use it on Itqan

1. Open Percentage calculator.
2. Choose increase, decrease, or discount.
3. Enter original value and percentage.
4. Pick currency if you want (optional — leave blank for plain numbers).
5. Click Result for final value and change amount.
6. Optional: save the result panel as an image for your records.

No registration, no file upload — everything runs in your browser session.

Numeric examples

These cases mirror what you might enter in the tool. Verify one by hand if you are learning the math:

Worked example — tax on 1,000: 1,000 × 15 ÷ 100 = 150 added → total 1,150. The 15% tax quick button switches to increase mode and fills 15% for GCC-style VAT-style additions on a subtotal.

Quick shortcuts

Three preset buttons sit below the rate field — each sets the mode and percentage in one tap:

• 15% tax — switches to increase, rate 15%. Common in Saudi Arabia and the GCC when adding VAT-style tax to a subtotal.
• 10% discount — switches to discount, rate 10%. Typical retail promo (“10% off everything”).
• 15% tip — switches to increase, rate 15%. Standard restaurant gratuity in many countries.

Shortcuts save taps on mobile — open the tool in the store aisle, enter the shelf price, hit 10% discount, and read the final price before checkout.

Vs other Itqan tools

Use this tool for quick “what-if” math on one amount; use the VAT calculator for tax-inclusive vs tax-exclusive invoicing.

Common mistakes

Mixing increase and discount

+10% then −10% does not return to the start — percents compound on different bases. Example: 100 + 10% = 110, then −10% of 110 = 99, not 100.

Applying discount twice

“Extra 20% off already reduced price” means 20% of the current price, not the original tag. Run two calculations: first discount, then use the result as the new original for the second.

Confusing markup with margin

40% markup on cost ≠ 40% margin on selling price. Always state which base the percent applies to.

Skipping currency

Numbers are correct but missing symbols confuse multi-currency reports. Select SAR, AED, or USD when sharing screenshots with colleagues.

Using for full VAT invoices

For formal VAT line items, seller details, and invoice layout, use VAT calculator or Invoice calculator.

Practical tips

Compare two store offers

Compute final price after each store’s discount — “20% + 10%” ≠ “30%”. Store A: 500 − 20% = 400, then −10% = 360. Store B: 500 − 30% = 350. Store B wins by 10.

Reverse-check a receipt

Decrease mode cannot cleanly strip tax from a tax-inclusive total — use VAT tools. For tax on top of 1,000, increase mode confirms the breakdown.

Save the result

Use the save-as-image button or copy the numbers into email, chat, or a spreadsheet.

On mobile

Responsive layout — handy while shopping in store. Preset buttons reduce typing on a small keyboard.

Pre-calculation checklist

Thirty seconds of review avoids wrong-mode errors:

• Correct mode: increase for tips/tax/markup, discount for sale prices, decrease for reductions not labeled as retail discounts.
• Original value is the right base (pre-tax subtotal for tax-on-top, tagged price before coupon).
• Rate is entered as a plain number (15 for 15%, not 0.15).
• Currency selected if the result goes into a report or message to someone else.
• For stacked promotions, plan two separate calculations — not one combined percent.
• Discount rate does not exceed 100% (the tool validates this).
• Result makes intuitive sense — a 10% discount on 200 should be near 180, not 2,000.

FAQ

Summary

The percentage calculator on Itqan Tools handles increase, decrease, and discount on any amount — with optional currency and one-tap presets for 15% tax, 10% discount, and 15% tip. Use it for store sales, salary raises, restaurant tips, and retail markup without memorizing formulas. Calculations run free in your browser with no account and no file upload. For formal VAT invoices or multi-line bills, switch to the VAT calculator or Invoice calculator. Run through the checklist, pick the right mode, and click Result.

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• VAT calculator
• Invoice calculator
• Loan calculator
• Currency converter