Unit Economics

LTV / CAC Ratio Calculator

The fastest unit-economics health check in eCommerce. Enter your numbers, see if your customers are worth more than they cost — and how long it takes to get your money back.

Your numbers

$

Average order value, before discounts.

%

After COGS, packaging, shipping. Pre-ads.

Average orders per customer.

mo

Average gap between purchases.

$

Total ad spend / new customers.

Your unit economics

LTV / CAC ratio
2.57 : 1

Above 3:1 is the rule of thumb for sustainable growth.

LTV
$90.00

Gross profit per customer over lifetime.

CAC payback
4.7 mo

Months until a new customer breaks even.

Profit / order
$30.00
What this means

Below 3:1 is the danger zone. You're recovering CAC but barely funding growth. Most stores in this band have a hidden margin leak — check returns, shipping, or a spike in CAC.

What LTV / CAC really tells you

The metric in one sentence

LTV / CAC is the ratio between how much gross profit a customer brings you over their lifetime (LTV) and what you paid to acquire them (CAC). Above 1:1 you're profitable on each customer; above 3:1 you have room to grow; below 3:1 you're either burning cash or running an unsustainable promo treadmill.

The math (and the trap)

LTV = AOV × gross margin × lifetime orders. CAC = total acquisition spend / new customers. Easy on paper. The trap: most founders use revenue, not gross profit, to compute LTV. That inflates the ratio by 2-3x and makes everything look healthier than it is. Your LTV is what's left *after* COGS, packaging, shipping, fees — pre-ads. Anything else is fiction.

Why payback period matters as much as ratio

A 5:1 ratio over 5 years is meaningless if you don't have the cash to wait 5 years. Payback period — months until a new customer's gross profit covers their CAC — is what dictates how fast you can scale. Healthy DTC brands target <12 months payback, ideally <6 for ad-funded growth. Beyond 18, you need outside capital or an unusually patient cap table.

Three levers to fix a broken ratio

Raise AOV (bundles, free shipping thresholds, upsells), increase lifetime orders (post-purchase flows, subscription, replenishment reminders), or reduce CAC (better creative, lower-cost channels, organic). Cutting prices to lift conversion almost always makes the ratio worse — you're trading margin for marginal volume.

When to recompute

After every major channel change, every quarter, and after any promo cycle. Black Friday traffic distorts CAC and LTV in opposite directions for months — re-baseline once cohorts mature.

Track this without spreadsheets.

Profit Tracker computes LTV, CAC, ratio, and payback per cohort, per channel, in real time — connected to your Shopify store and ad accounts.

LTV / CAC Ratio Calculator (Free, No Signup) | Ecombone