LTV:CAC Ratio

What LTV:CAC Ratio Means

LTV:CAC ratio is the dollars a customer pays over their lifetime divided by the dollars spent acquiring them. It is the headline number a SaaS finance team uses to argue the business is fundable. Three to one is the conventional floor — below that you are paying too much to land logos that do not pay you back; above five and you are probably under-investing in growth.

The ratio puts two of the messiest numbers in SaaS into a single fraction. Customer Lifetime Value usually expands as retention improves. Customer Acquisition Cost usually inflates as you scale paid channels. The ratio compresses as you grow, which is why early-stage decks show 8:1 and Series C decks suddenly show 3.4:1.

How LTV:CAC Is Calculated

The standard formula:

LTV:CAC = (ARPA × Gross Margin ÷ Churn Rate) ÷ (Sales & Marketing Spend ÷ New Customers Acquired)

ARPA is average revenue per account. Gross margin is the percent contribution after COGS. Churn is the period gross revenue churn rate. The CAC denominator should include fully loaded sales and marketing — salaries, tools, ad spend, agency fees — not just paid media.

Two finance teams can produce 2.4:1 and 7.1:1 on identical books depending on which column they pick.

Worked LTV:CAC Example

A B2B SaaS company has $24,000 ARPA, 80% gross margin, and 8% annual gross revenue churn. LTV is $24,000 × 0.80 ÷ 0.08 = $240,000. The company spent $14M on sales and marketing last year and added 220 new logos, putting CAC at $63,636. LTV:CAC = $240,000 ÷ $63,636 = 3.77:1.

Swap Gross Revenue Retention for Net Revenue Retention at 112% — pretending churn is negative 12% — and LTV inflates to roughly $1.6M and the ratio jumps to 25:1. Same business.

When Sales Orgs Use LTV:CAC

Finance and the board look at it quarterly. A ratio sliding below 3:1 triggers conversations about quota assignment, channel mix, and whether the next sales hire pays for themselves. RevOps owns the data plumbing — defining what counts as a new customer, allocating shared-services cost, deciding whether expansion bookings inflate the numerator.

Heads of Sales rarely cite LTV:CAC in pipeline reviews, but it sets the ceiling on their hiring plan. A company at 4:1 with a 14-month CAC Payback Period can fund headcount aggressively. One at 1.8:1 will freeze backfills no matter how strong the pipeline looks. Recruiters watch the ratio in board decks to read whether the org is hiring or quietly contracting.

Common LTV:CAC Gaming Patterns

The ratio is one of the most-gamed numbers in SaaS finance, because both inputs are estimates the company controls.

Cohort cherry-picking: choose the 90 days with the best retention and lowest CAC, then call it current run rate. Excluding paid media: report "organic CAC" by stripping ad spend from the denominator. Counting expansion as negative churn: use Net Revenue Retention above 100% to push LTV toward infinity. Ignoring fully-loaded cost: omit sales leadership salaries, tools, and BDR base pay from CAC entirely.

The cleanest sanity check: gross margin LTV, fully-loaded trailing-twelve-month CAC, gross revenue churn. If the number passes there, it passes everywhere.