Mcfly Ads

Free break-even ROAS calculator

Break-even ROAS ≈ 1 ÷ contribution margin. Enter spend and sales to see Total ROAS against that floor — and spend headroom. Same math as the Shopify desk. No account.

1 ÷ margin = break-even. Did sales ÷ spend clear it?

Also: MER calculator · installable (PWA)

Runs in your browser · offline

Break-even ROAS calculator

Set margin first — break-even falls out. Then compare to sales ÷ spend. Readout updates live.

$
$
%

MER / Total ROAS

3.46×

$221,296 ÷ $64,000

Break-even ROAS 2.86× 1 ÷ 35% margin
Spend headroom +$13,454 room before break-even

Above break-even — protect the mix.

At 35% margin, $221,296 in sales breaks even at $77,454 of ad spend. You're spending $64,000 — ads left $13,454 of contribution after covering themselves.

Honest catch. Break-even is a floor from margin — not which ad earned the sale. Compare Total ROAS to that floor; that’s the Budget call finance can defend.

Keep it on your home screen

Install once.
Read Total ROAS anywhere.

Install as a PWA — works offline after first load. No login. Numbers stay on your device.

  1. Chrome / Edge

    Install from the menu

    Open the browser menu and choose Install Mcfly Ads (or the install icon in the address bar). It opens in its own window.

  2. Safari · iOS

    Add to Home Screen

    Tap Share, then Add to Home Screen. Launch it like any app — the calculator runs without a connection.

  3. Offline

    Works with no signal

    A service worker caches the page after first load, so Total ROAS and break-even keep calculating on a plane, in a warehouse, anywhere.

Nothing you type leaves your device. The calculator does no tracking and stores no numbers on a server.

Who this is for

One formula.
Everyone who buys ads.

Shopify operators between installs

Want the number before connecting a store? Feel the exact Total ROAS math here, then run it live on your data inside the embedded app.

Service businesses without a store

No Shopify, no checkout pixel, no problem. Sales ÷ spend works for agencies, local services, and info products just the same.

Agencies pitching honesty

Show Total ROAS and break-even in ten seconds — a number the client can defend to finance, without path credit.

Optional

Email me these numbers

We store the snapshot and reply when we can. Not a fake “you’re on the list” screen.

When you're ready for live data

The desk, on your real sales

Calculator = manual. Shopify app pulls sales; you paste Meta + Google spend from Sheets — then Total ROAS vs break-even every week, one allocation call. Same math. No ad OAuth.

Install free App Store install steps How it works

Later $39/store/mo flat via Shopify Billing — announced before anything charges. Not forever-free. Not a GMV tax. Not a pixel.