Percentage Calculator

Three percent questions, one toggle row

Tip math is X% of Y. Raise math is increase mode. Exam score "what percent" is the third mode. Defaults in mode 1: 20% of 250 = 50.00.

Increase/decrease adds a direction dropdown. +20% on 250 = 300. -20% on 250 = 200.

Copy writes the detail line from the secondary card.

Finance pages extend the same math

Markdown percent on a list price is the Discount & Sales Price Calculator with sale price output.

Tax on a subtotal uses rate as percent in the VAT / GST Tax Calculator.

ROI percent from dollar outcomes is the ROI Calculator when you have initial and final balances.

Sanity-check inputs before quoting

Percent without "%" sign in the field: type 20 for 20%, not 0.20.

Stacked discounts (20% then 10%) are not one 30% pass. Run twice or multiply factors (0.8 x 0.9).

Word-count trim targets pair with the Word & Character Counter after you compute the cut.

Frequently Asked Questions (FAQ)

What do the three modes do?

X% of Y: result = Y x (X/100). Default 20% of 250 = 50. Increase/decrease: new = Y x (1 +/- X/100). What percent: (X/Y) x 100 when Y is not zero.

What happens if Y is zero in "what percent"?

Division by zero is blocked. Alert fires, results show n/a, copy disabled.

How is this different from the discount calculator?

Discount tool pairs list price with sale price in retail language. This page is general percent arithmetic. Use the Discount & Sales Price Calculator for shelf tags.