Net and gross are different bases
When VAT is added to a net price, tax equals net multiplied by the rate; extracting tax from a gross price requires division by one plus the rate.
Multi-rate VAT invoice and reconciliation
Calculate the customer total and the tax position behind it
Apply standard, reduced, and zero rates, allocate a discount, tax shipping separately, extract VAT from an inclusive price, and reconcile output VAT with input credits and adjustments.
Plan with context
VAT arithmetic is simple only when every line uses the same treatment.
Real invoices mix standard, reduced, zero-rated, and exempt supplies, while discounts, freight, input credits, and jurisdiction-specific rules determine the amount ultimately remitted.
Mixed rates create an effective rate
The invoice-wide effective percentage is a weighted result and usually differs from every statutory line rate.
Discounts usually reduce the base
A discount applied before the tax point commonly reduces both taxable net and VAT, but allocation and timing rules vary.
Freight may follow the supply
Shipping and handling can be taxable at the main supply’s rate, another rate, or under separate rules depending on jurisdiction and contract.
Input credits reduce remittance
Output VAT collected from customers and eligible VAT paid to suppliers are reconciled; a credit does not change the customer’s invoice total.
Zero-rated is not always exempt
Both may produce no output VAT, but registration, reporting, and input-credit consequences can differ materially.
Included
Standard, reduced and zero-rated amounts, separate rates, allocated discount, shipping and rate, reverse extraction, input VAT, adjustments, payable amount, effective rate, scenarios, Chart.js visuals, and line worksheet.
Not included
Country-specific place-of-supply rules, registration thresholds, reverse charge, imports, exemptions, partial recovery, bad-debt relief, invoice rounding mandates, filing dates, penalties, or currency conversion.
Use it well
Classify each supply first, verify whether prices are tax-inclusive, preserve valid supplier invoices, and reconcile the calculator with the jurisdiction’s return form.