Free tool · Metric 3 of the Scaling Scorecard
The 90-Day LTGP:CAC Grader.
The LTV:CAC calculator that grades on gross profit, not revenue. Two numbers in, one grade out - against the same green/yellow/red thresholds we run before budget decisions on managed accounts.
Built by HoloGrowth - 50+ DTC brands, $50M+ partner revenue. Runs entirely in your browser - nothing you type is stored or sent anywhere. Analytics records only that the tool ran and its grade band - never your numbers.
30 seconds, two required numbers
Grade your ratio.
90-day lifetime gross profit per new customer, divided by what it cost to acquire them. The grade and the thresholds are identical to the LTGP:CAC row in the Scaling Scorecard calculator.
Revenue a new-customer cohort generates in its first 90 days minus COGS, fulfillment, payment fees, and discounts - divided by the number of customers in the cohort. Before ad spend.
Acquisition spend divided by new customers acquired - backend count, not platform attribution.
Total ad spend divided by all customers, new and returning. Shown for comparison only - it is never graded, because it flatters the ratio whenever you have repeat buyers.
The grade is only as good as the inputs. If your CAC comes from platform dashboards, read The Agency Incentive Problem first - in the accounts we've audited, Google Ads typically overstates its contribution by 80-90% and Meta typically understates by 20-80%.
The bands, in plain language
What your grade means.
This is the metric that lets you scale when day-one ROAS looks ugly - and the cohort signal that says stop.
Scale.
A weak first order is fine when the 90-day ratio clears 2 - the customer comes back. At 3.0:1 or above you're in the aggressive zone: room for 20-30% budget steps, if the other four metrics agree.
Hold.
Not losing money, not earning the right to scale. More budget buys more of the same problem - improve retention, repeat rate, AOV, or acquisition quality first, then re-run the number.
Fix first.
Ninety days in, a customer hasn't returned 1.5x their acquisition cost in gross profit. Fix retention or acquisition quality before spending another dollar on scale.
One grader grades one metric. The full Scorecard runs all five - CM3, nCAC, LTGP:CAC, payback, and revenue split - because a green ratio with a red payback period is still a cash problem. Get the free Scaling Scorecard or score all five now. More free tools: the ROAS calculator, the MER calculator, the CAC payback calculator, and the spend ceiling calculator.
What is LTGP:CAC?
LTGP:CAC is the ratio of the gross profit a new customer generates in their first 90 days to what it cost to acquire them. LTGP stands for lifetime gross profit. This grader measures it on a fixed 90-day cohort window, on gross profit rather than revenue. Revenue-based LTV flatters every input; a forecast window flatters every assumption. A ratio of 2.0:1 means a customer returns twice their acquisition cost in real margin inside a quarter.
It answers the question platform ROAS cannot. Not "did the first order cover the ad" - but "is each new customer worth buying at this price, once the repeat behavior you can actually verify is counted."
A worked example, start to finish.
Say your average order is $70 and your gross margin - after COGS, shipping, and payment fees - is 60%. First-order gross profit: $42. Your cohort data shows a new customer places 1.7 orders in their first 90 days. So 90-day gross profit per new customer is $42 x 1.7 = $71.40. That is the first input.
Now the other side. Last month you spent $34,000 on ads and acquired 1,000 genuinely new customers: new-customer CAC is $34. The ratio: $71.40 / $34 = 2.1:1 - just over the GREEN line. Scale carefully, and watch the other four scorecard metrics.
Same brand, but CAC drifts to $48 as spend rises. Now it is $71.40 / $48 = 1.49:1 - RED by a hair. Nothing about the product changed; the acquisition price did. That is the drift this grader is built to catch early, and why it belongs in the monthly rhythm, not a one-off check.
Why this calculator grades differently
Gross profit, not revenue. 90 days, not a forecast.
The standard LTV:CAC formula puts revenue in the numerator. That version is comfortable and flattering - and wrong for budget decisions, because revenue doesn't pay for ads. Gross profit does. Picture a cohort at $120 of revenue per customer in 90 days against a $40 CAC: on revenue the ratio reads 3:1, textbook green. Run it on gross profit at a 35% margin and the same cohort is $42 - a 1.05:1 that grades deep red. One brand, one cohort, two opposite calls.
The 90-day window is the honesty mechanism. A 12-month LTV number is a bet on customers who haven't bought yet; if the bet is wrong, the ad budget it justified is already spent. Ninety days is short enough to check against the bank account before the next budget move - and long enough to catch the early repeat behavior that actually predicts the rest.
And the denominator matters as much as the numerator. Blended CAC spreads this month's spend across buyers you already paid for once, so it always reads friendlier than the true cost of a stranger. The grade here runs on new-customer CAC; the blended field exists for comparison, never for the verdict.
"No one is accurate. The only person is accurate is my real numbers. My bank credit... my balance sheet, that's the accurate number, not Facebook... not Shopify."
LTV:CAC questions, answered straight.
On the 90-day LTGP:CAC version of the ratio - gross profit, not revenue - 2.0:1 or above is green: scale. 1.5 to 1.9 is yellow: hold and improve the ratio before adding spend. Below 1.5 is red: fix retention or acquisition quality first. At 3.0:1 or above you're in the aggressive zone. The classic 3:1 benchmark quoted elsewhere is usually a revenue-based calculation, which is a different and more flattering version of the ratio.
LTV:CAC usually compares revenue per customer to acquisition cost. LTGP:CAC compares lifetime gross profit - revenue minus COGS, fulfillment, payment fees, and discounts - to acquisition cost. The difference is your margin. A 3:1 revenue ratio on a product with a 40% gross margin is a 1.2:1 gross-profit ratio, which grades red, not green. Revenue doesn't pay for ads; gross profit does, so the grader runs on gross profit.
New-customer CAC. Blended CAC divides total spend by all customers, including repeat buyers you already paid to acquire once - so it's lower whenever you have repeat buyers, and the ratio it produces is prettier than reality. Blended CAC hides the truth. The grader accepts blended CAC as an optional comparison input so you can see the size of the gap, but the grade runs on new-customer CAC.
Because you can verify 90 days against cash in the bank. A 12-month LTV projection asks you to fund today's ad spend with revenue you're forecasting, not revenue you've observed - and if the projection is wrong, you find out after the cash is gone. Ninety days is long enough to capture early repeat behavior and short enough that the number is real when you make the budget decision.
A red ratio has two levers: the numerator (90-day gross profit - improved through retention, repeat purchase rate, AOV, and margin) and the denominator (new-customer CAC - improved through offer, creative, and acquisition quality). Which lever is yours is what the other four Scorecard metrics point to - the free Scaling Scorecard has all five with the exact thresholds. If you're at $1M+/year and spending $30K+/month on ads, a free Strategy Call will name the constraint faster.
They're the same green/yellow/red bands as the E-Commerce Scaling Scorecard - the 5-metric decision tool we run before every budget move on managed accounts. 90-day LTGP:CAC is metric 3 of 5; the calculator on the Scorecard page grades all five together.
Yellow or red? The fix comes by email.
Ecom Growth Insider: one specific tactic per issue, twice a week, from real partner accounts - unit economics, retention, creative, offers. Subscribing also gets you the E-Commerce Scaling Scorecard PDF with all five metrics and every threshold. Unsubscribe anytime.
The rest of the toolkit.
Each one answers a different question in the same system. Same rules everywhere: your numbers stay in your browser.
CAC Payback Calculator
How many days until an acquired customer pays back their own CAC.
The Honest ROAS Calculator
Two numbers in, your ROAS out - add total revenue and your blended MER appears next to it.
MER Calculator
Total revenue over total spend - the number no attribution model can inflate.
Breakeven ROAS Calculator
The ROAS you must clear before a single ad dollar is profit.
Spend Ceiling Calculator
Your marginal ROAS floor and the coverage line that decide how far spend can scale.
The Scaling Scorecard
All five metrics in one pass - the scale / hold / fix / kill thresholds.
Already at $1M+ and spending $30K+/month?
Green ratio, but you don't trust the inputs?
That's the usual situation at your scale: the ratio is fine, the numbers behind it aren't - platform CAC, guessed margins, blended everything. On a free 30-minute call we sanity-check your numbers and name your most likely constraint live.
For 7- and 8-figure ecom brands: $1M+/year, $30K+/month on ads. 8 strategy calls a week.
Use this calculator in your own content.
You're welcome to link to this grader or cite its thresholds and examples in your own article, newsletter, or course - just credit HoloGrowth with a link back to this page.
Free 90-Day LTGP:CAC Grader by HoloGrowth: https://hologrowth.com/tools/ltgp-cac-grader/