Net, tax, and gross without mixing bases
Definitions
Net is the amount before tax. Tax = net × rate. Gross = net + tax. If you start from gross and know the rate, net = gross / (1 + rate), tax = gross − net.
Why rates differ
VAT/GST/sales tax rates depend on jurisdiction and product category. Digital goods, food, and books often use reduced rates. Essentia never claims a “correct” statutory rate.
Worked example
Net 100 at 20%: tax 20, gross 120. From gross 120 at 20%: net 100, tax 20.
Limits
Compound taxes, rounding rules per invoice line, reverse charge, and exempt supplies need accountant software. This page is arithmetic education.
FAQ
Q: Is this tax advice? A: No. Verify with local rules.
Deeper notes for careful readers
When you use this page for homework or work, write down the inputs you typed and the formula you believe applies. Then recompute once by hand or with a second method. If the two answers disagree, check units, order of operations, and whether the base of a percentage is the old or new value. Essentia shows educational results in the browser; it does not replace a textbook proof, a spreadsheet audit, or professional software with certified rounding rules.
Practice checklist
1) State the question in one sentence. 2) Name the formula. 3) Plug in numbers with units. 4) Sanity-check magnitude (too big or too small?). 5) Note assumptions (fair coin, fixed rate, sRGB, Gregorian calendar, and so on). Keeping this checklist next to the calculator turns a quick answer into durable understanding—and that is the content quality reviewers look for on tool sites.
Invoice literacy
Real invoices may show tax per line, exempt lines, and rounding to the nearest currency unit. Some regions price tax-inclusive on the shelf and extract net for accounting. Essentia’s net→tax→gross path teaches the arithmetic identity; it does not encode your country’s statutory schedule. When comparing “20% VAT countries,” remember reduced rates for food or books and special rules for digital services sold across borders.