Finance & Australia

GST Calculator

Business

VAT / GST Calculator

Price basis first

Net price (currency)Enter the known price. Use net price when adding tax, or gross price when removing included tax.VAT / GST rate (%)Use the rate that applies to the item and country you are checking.

Gross price after tax$144.00Updates as you type · adding tax at 20%

$120.00Net price$24.00Tax amount$144.00Gross price20%Entered rate

$120.00 net x 1.2 = $144.00 gross. Currency, invoice rounding, exemptions, mixed-rate baskets and filing rules are outside this arithmetic check.

Add taxRate 20%Net $120.00Tax $24.00

Audit mode code0 adds tax, 1 removes included tax

Mode codeEnter 0 to add tax to a net price, or 1 to remove included tax from a gross price.

Use the segmented buttons for normal work. The mode field stays printable and auditable for the underlying formula.

Live result$144.00Add tax · $120.00 net · $24.00 tax · $144.00 gross.

Formula used

Add tax: gross price = net price × (1 + tax rate ÷ 100); tax amount = gross price − net price. Remove included tax: net price = gross price ÷ (1 + tax rate ÷ 100); tax amount = gross price − net price.

This is the method behind the answer, so the result can be checked rather than simply trusted.

Live math canvas

Your numbers, formula and explanation together

At 20% VAT/GST, 120.00 entered as net price gives net 120.00, tax 24.00, and gross 144.00.

Formula applied

The exact method behind this answer

CalculationTime keeps the method visible so the number can be checked instead of blindly trusted.

Add tax: gross price = net price × (1 + tax rate ÷ 100); tax amount = gross price − net price. Remove included tax: net price = gross price ÷ (1 + tax rate ÷ 100); tax amount = gross price − net price.

Multiplier1 + 20% / 100 = 1.2
Gross price120.00 x 1.2 = 144.00
Tax amount144.00 - 120.00 = 24.00

Your live breakdown

Current inputs in the calculation

These values come from the controls above and update when the calculator changes.

Price amount: 120 currency
VAT / GST rate: 20 %
Mode: 0 add tax, 1 remove tax: 0

Resulting answer

24.00 tax

Mode: net price. Net 120.00; tax 24.00 at 20%; gross 144.00.

Multiplier: 1 + 20% / 100 = 1.2
Gross price: 120.00 x 1.2 = 144.00
Tax amount: 144.00 - 120.00 = 24.00

Assumptions used

What this answer assumes

Set mode to 0 for net-to-gross or 1 for gross-to-net. Confirm the local tax rate before using the result in records.

The entered rate is the applicable VAT, GST or sales-tax-style percentage.
The entered price is treated as net before tax.
Currency symbols, exemptions, reverse charge, imports and multi-rate baskets are outside this arithmetic check.

Master’s Tip

How to use the result well

Master’s Tip: keep the tax basis visible on quotes and purchase records. A price that says “120” is not enough for bookkeeping unless the report also says whether 120 was net, gross tax-inclusive, or tax-exempt.

Printable record

What belongs in the saved calculation

These rows are ready for a report, worksheet, quote note or audit trail.

Input price: 120.00
Tax rate: 20%
Net: 120.00
Tax: 24.00
Gross: 144.00

What-if check

Rate comparison

Compare common rates against the same entered amount. This helps show whether the price was treated as net-before-tax or gross-tax-inclusive before the report is printed.

Rate	Net	Tax	Gross
0%	120.00	0.00	120.00
5%	120.00	6.00	126.00
10%	120.00	12.00	132.00
20%	120.00	24.00	144.00

Visual proof

Net + tax = gross

Mode 0 adds tax to a net amount. The printed report keeps that basis beside the result.

Visual grid

This number is one point on a larger pattern

VAT / GST is not just a final answer. It is a step on a line: before and after, input and output, assumption and result.

Micro-timehours, minutes, shiftsHuman scaledays, weeks, projectsMacro-timemonths, years, calendars

InputFormulaResult

24.00 tax

CalculationTime keeps the path visible: the input, the method and the final number belong together.

24.00 taxMode: net price. Net 120.00; tax 24.00 at 20%; gross 144.00.

Inputs

Price amount: 120 currency
VAT / GST rate: 20 %
Mode: 0 add tax, 1 remove tax: 0

Method

To remove 20% VAT from a gross price of 120, divide 120 by 1.20 to get a 100 net price. The tax amount is 120 − 100 = 20. To add 20% to a 100 net price, multiply 100 by 1.20 to get a 120 gross price.

Assumptions

The entered rate is the applicable VAT, GST or sales-tax-style percentage for the item being checked.
Mode 0 treats the entered price as net before tax; mode 1 treats the entered price as gross tax-inclusive.
Currency symbols, invoice rounding rules, exemptions, reverse charge, import duties and multi-rate baskets are not handled.
This calculator is an arithmetic aid only, not tax, accounting or compliance advice.

Notes

Use this space on the printed report for client, supplier, classroom, job-location, measurement, quote or approval notes.