calculatorpro

After the fees come out, what do you actually keep?

Enter what a product costs you and what you plan to charge. You'll see your margin, profit per unit, ROI and break-even price on eBay, Amazon and Shopify — side by side, after every fee each one takes.

  • Free, with no limits
  • No account needed
  • Nothing leaves your browser
Where do you sell?

Loaded with an example so you can see how it works — £12.00 cost, £29.99 price. Type over any field with your own numbers.

1Select your product
2Enter your costs & price
£
£
£

Cost Summary

Product cost£12.00
Shipping£3.50
Payment (2.9%+30p)£1.17
Base cost (before platform fee)£16.67

Target Price Calculator

What must you charge to hit a desired margin?

%

eBay

£27.07

Amazon

£25.83

Shopify

£21.91

3Your platform results

Best Platform

Shopify

Margin

44.4%

Profit/unit

£13.32

ROI

80%

eBay(12.95% fee)
Good

30.8%

margin

Profit/unit

£9.22

ROI

44%

×1 total

£9.22

Platform fee £5.27·Payment £0.00·Total cost £20.77Break-even £19.01
Amazon(15.00% fee)
Good

33.3%

margin

Profit/unit

£9.99

ROI

50%

×1 total

£9.99

Platform fee £4.50·Payment £0.00·Total cost £20.00Break-even £18.24
Shopify(0.00% fee)Best
Good

44.4%

margin

Profit/unit

£13.32

ROI

80%

×1 total

£13.32

Platform fee £0.00·Payment £1.17·Total cost £16.67Break-even £16.27
4Visual analysis

Where does your £29.99 go?

£30

sell price

Supplier Cost
£12.00(40%)
Shipping
£3.50(12%)
Platform Fee
£5.27(18%)
Payment Fee
£0.00(0%)
Profit
£9.22(31%)
Net margin30.8%

Platform Comparison

eBay

30.8%

£9.22/unit

Amazon

33.3%

£9.99/unit

Shopify

44.4%

£13.32/unit

Total Profit by Units Sold

Hover any point to see exact profit. Red line = break-even.

Showing 1 – 30 units
eBay
Amazon
Shopify

Saved Calculations

Saving is not available yet

How it works

Three numbers in, every platform compared. Nothing to set up.

  1. STEP 1

    Enter what it costs you

    The supplier price and what you paid to get it delivered to you. Buying in dollars or yuan? Switch currency and it converts at the live rate.

  2. STEP 2

    Enter what you’ll charge

    Your selling price, and how many units you expect to shift. Or work backwards — tell it the margin you want and it gives you the price.

  3. STEP 3

    Compare the platforms

    Margin, profit per unit, ROI and break-even for all three at once, with a breakdown of where every pound of the sale price actually goes.

A worked example

You buy a stock pot for £12.00, pay £3.50 to get it delivered to you, and list it at £29.99. That looks like £14.49 of profit. Here is what each platform actually leaves you.

Profit comparison across eBay, Amazon and Shopify for a £29.99 sale price
PlatformTheir feePaymentYou keepMargin
eBay£3.88£1.17+£9.4431.5%
Amazon£4.50£1.17+£8.8229.4%
ShopifyBest£0.00£1.17+£13.3244.4%

The same product, the same price — and a £4.50 per-unit gap between the best and worst platform. At 500 units that is £2,250.

What this does and doesn't count

It is exact about the fees it models and silent about the rest. Knowing which is which is the difference between a useful number and a misleading one.

Counted

  • Platform commission — eBay 12.95%, Amazon 15%, Shopify 0%
  • Payment processing — 2.9% + 30p per sale
  • What the product cost you
  • Shipping in to you, including from overseas
  • Currency conversion at the live rate, or one you set

Not counted

  • VAT — the big one — if you’re registered, every margin here is overstated
  • Amazon FBA fees — fulfilment and storage, which can exceed the referral fee
  • Advertising — sponsored placement is now a normal cost of selling
  • Returns and refunds — a 5% return rate removes roughly 5% of gross margin
  • Delivery to your customer — only shipping in to you is captured
  • Shopify’s monthly plan — the 0% is per-transaction commission only

Common questions

Do I need an account?

No. The calculator is completely free and works without signing in — your calculations save to your own browser. An account only exists so your saved work follows you to another device.

Which fees does it include?

The platform commission (eBay 12.95%, Amazon 15%, Shopify 0% per transaction) plus payment processing at 2.9% + 30p, applied to the sale price. It also counts what the product cost you and what you paid to get it delivered to you.

Does it account for VAT?

Not yet — and this matters. If you are VAT-registered, 20% of a VAT-inclusive sale price is not yours to keep, so every margin shown here is higher than what you will actually see. A £29.99 sale nets £24.99 before any other cost. A VAT toggle is the next thing being built.

Where do the fee rates come from?

They are each platform’s standard published rates. Both eBay and Amazon vary their commission by category, and negotiated or promotional rates exist, so treat these as a well-informed default rather than your exact account.

Why is Shopify shown at 0%?

Shopify takes no per-transaction commission of its own — you still pay the payment processor. It does charge a monthly subscription, which this calculator does not spread across your units, so Shopify looks slightly better here than it will at low volume.

What happens to what I type in?

Nothing leaves your browser unless you sign in and save. There is no tracking of anonymous use at all.