Open GST Calculator

Overview

To work out GST on any figure, press Ctrl + G (Windows) or Cmd + G (Mac) from any page to open the GST Calculator → type a figure into the Amount box → read the GST-inclusive breakdown on the left and the GST-exclusive breakdown on the right. Click any result to copy it.

Open the calculator and enter an amount

Press the shortcut

From any page in Keyhook, press Ctrl + G (Windows) or Cmd + G (Mac). The GST Calculator opens in a pop-up.

Type in the amount

Enter the figure you're working with in the Amount box in the middle. There's no button to press — the breakdown updates live as you type.

Note: The shortcut works from anywhere in Keyhook, so you can pop the calculator open while you're mid-way through entering an invoice or a charge without losing your place.

Read the GST breakdown

Treat your figure as GST-inclusive (left)

The Including side, to the left of the amount, treats your figure as a GST-inclusive total: GST part of 15% is the GST already inside it, and Amount minus GST is the price before GST.

Treat your figure as GST-exclusive (right)

The Excluding side, to the right, treats your figure as a pre-GST price: GST at 15% is the GST to add, and Amount + GST is the total once GST is added.

Note: The calculator is fixed at New Zealand's 15% GST rate and can't be changed, and figures are rounded to the nearest cent. It's a quick reference only — the GST actually recorded against a charge comes from the invoice editor's own totals.

Copy a figure to use elsewhere

Click the result you want

Click any result box. A green Copied flag appears and that figure is copied to your clipboard.

Paste it where you need it

Paste the copied figure straight into an invoice, an email or a spreadsheet.

Close the calculator

Click Cancel

Click Cancel (or press Esc, or click outside the pop-up) to close it. Nothing is saved — it's a calculator, not a form — so you can reopen it any time with the shortcut.

Frequently asked questions

What GST rate does it use, and can I change it?

It's fixed at New Zealand's 15% GST rate and can't be changed — the pop-up shows "GST rate fixed at 15%" at the bottom.

Do I enter a GST-inclusive or GST-exclusive amount?

Either — you enter one figure and get both readings at once. The Including side (left) treats it as a GST-inclusive total, and the Excluding side (right) treats it as a pre-GST price.

Can I use it while I'm entering an invoice?

Yes. The shortcut works on any page, and the invoice editor even prompts you to press Ctrl + G while you're entering charge amounts.

How do I copy a result?

Click any of the result boxes — the figure copies to your clipboard and a green Copied flag confirms it. Then paste it wherever you need.

How do I close the calculator?

Click Cancel, press Esc, or click outside the pop-up. There's nothing to save, so it just closes.