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Free tools for local retailers

Retail calculators that answer real shop-floor questions

Check a price, test a discount, find your break-even and see what slow stock is costing you. No sign-up. Nothing you enter leaves your browser.

GST

Margin and markup calculator

Margin and markup are not the same number. Check the real margin on a price, or work out the shelf price that hits your target margin.

What you pay the supplier per unit, before GST.
$
The price on the ticket.
$
Gross margin you want on this item.
%

How it works

Margin is profit as a share of the selling price ex GST. Markup is profit as a share of cost. A 100% markup is a 50% margin.

GST is removed from the shelf price before any calculation, because GST is not your money.

Shop-floor tip

Quote margin, not markup, when you compare categories or talk to your accountant. Mixing the two is one of the most common pricing mistakes in small retail.

Discount impact calculator

A discount comes straight out of your margin. See how many more units you need to sell just to earn the same gross profit.

Your normal margin on the item or category.
%
Percentage off the normal price.
%
Optional. Used to show the target in units.
units

How it works

Your cost does not change when you discount, so every dollar off the price is a dollar off your profit. Extra volume needed = margin ÷ (margin − discount) − 1.

Shop-floor tip

Try a value-add instead: a gift with purchase or a bundle often protects margin better than a straight percentage off. Keep deep discounts for stock you genuinely need to clear.

Break-even calculator

Find the sales you need each month, week and trading day before the shop starts making a profit.

$
Include your own drawings if you want a true picture.
$
Power, insurance, software, phone, loan repayments.
$
%
days
Your average basket. Used to show customers needed per day.
$

How it works

Break-even sales (ex GST) = monthly fixed costs ÷ gross margin. Figures are shown inc GST as well, so you can compare them with your till takings.

Shop-floor tip

A small lift in average sale often moves break-even more than chasing extra foot traffic. One extra add-on item per ten customers adds up quickly.

Card fee cost calculator

Card fees are easy to ignore because they come out a little at a time. Compare what two merchant rates cost you over a year.

Card and tap payments only, not cash.
$
$
Percentage per transaction, plus any fixed cents per transaction.
%
c / txn
For example, a rate quoted by your bank or payment provider.
%
c / txn

How it works

Annual cost = (card sales × rate) + (number of transactions × fixed fee), over 12 months. Small differences in rate become large numbers over a year.

Shop-floor tip

Ask your POS provider whether they add their own fee on top of your bank's merchant rate. Tower Systems does not charge a transaction fee on any plan; your bank or payment provider's merchant fees still apply.

Stock turn and GMROI calculator

See how many times a year your stock sells through, how many days of stock you hold, and how much gross profit each dollar of stock earns.

For the whole shop or one category.
$
%
From your stock valuation report. Averaging a few months is best.
$

How it works

Stock turn = cost of goods sold ÷ average stock at cost. Days of stock = 365 ÷ stock turn. GMROI = gross profit ÷ average stock at cost.

Healthy figures vary widely by category, so compare against your own history first.

Shop-floor tip

Run this for each department, not just the whole shop. A strong average can hide one category that ties up most of your cash.

Dead stock cost calculator

Stock that is not selling still costs money: shelf space, cash, insurance and slow decline in value. Compare holding it with clearing it.

Items with no sales in, say, 120 days.
$
A common rule of thumb is 20–30% of stock value a year.
% / yr
months
Cash you expect back as a share of cost, after markdowns.
% of cost

How it works

Holding cost = stock value × annual rate × months ÷ 12. Clearance loss = stock value × (100% − recovery). The calculator compares the two and shows the cash you free up by clearing now.

Shop-floor tip

Cash freed from dead stock can be spent on lines that already sell. Check whether your POS flags slow stock automatically so it never builds up in the first place.

Want these numbers without the typing?

Tower Systems POS software tracks margin, stock turn and slow stock from your own sales data, and the Insights Dashboard flags dead stock and missed sales in plain language. Australian made and supported.

Book a free demo

About these calculators. Results are estimates for planning only and are not financial, tax or accounting advice. Talk to your accountant before making major decisions.

Calculations run in your browser. Nothing you enter is stored or sent anywhere.

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