VAT Calculator

Add VAT to a net price or extract it from a gross price.

How the calculator works

Adding VAT multiplies the net amount by (1 + rate): 100 at 15% becomes 115, of which 15 is tax. Removing VAT is the inverse and the part people get wrong — you cannot subtract the percentage from the gross. Because the tax was calculated on the smaller net figure, extracting it divides by (1 + rate): 115 gross at 15% yields a net of 100 and tax of exactly 15, whereas subtracting 15% of 115 would wrongly net 97.75. The calculator performs the division, then derives the tax as the difference, so net + VAT always reassembles into the exact gross you entered — the check every tax invoice requires.

Formula

Add: Gross = Net × (1 + rate)
Remove: Net = Gross ÷ (1 + rate), VAT = Gross − Net

Where:

  • Net — the price excluding VAT
  • Gross — the price including VAT
  • rate — the VAT percentage as a decimal (15% = 0.15)

Example

An invoice line of $100 net with 15% VAT: the tax is $15.00 and the gross total is $115.00. Now take a receipt that reads $230.00 inclusive at 15%: the net is 230 ÷ 1.15 = $200.00 and the embedded tax is exactly $30.00 — the amount a registered business can typically reclaim, and the figure the tax authority will expect on the return.

Frequently Asked Questions

Why can't I just subtract the VAT percentage from the gross?
Because VAT was computed on the net, not the gross. Subtracting 15% of $115 gives $97.75 — wrong. The correct extraction divides by 1.15, restoring the $100 net on which the original tax was calculated. The difference is real money on large invoices.
Which rate should I use?
The rate applicable to that product or service in your country — standard, reduced, or zero. Rates change by law; verify the current figure with your tax authority rather than relying on memory or old invoices.
Is sales tax calculated the same way?
The arithmetic of adding a percentage is identical, but US-style sales tax is normally added only at the final sale and is not usually embedded in shelf prices — so the 'remove' mode applies mainly to VAT/GST systems that quote tax-inclusive prices.
What about multiple rates on one invoice?
Calculate each line separately at its own rate and total the columns — mixing rates in a single calculation produces a wrong tax figure. This calculator is per-amount by design, matching how invoices are structured.