LTV:CAC Ratio

What it is

Lifetime value divided by acquisition cost. Below 1:1 you are paying more for patients than they will ever bring, and growth accelerates the loss. Around 3:1 is generally considered healthy. Well above 5:1 usually means you are under-investing in marketing rather than running a brilliant business — you could be buying more patients than you are.

Why it matters to your bottom line

• It is the difference between growth that funds itself and growth that consumes the practice. Two clinics with identical revenue can sit on opposite sides of that line.
• It settles arguments. Whether to raise prices, whether to spend more on ads, whether the loyalty programme is worth running — all of them resolve to their effect on this ratio.
• It is the mathematical form of the whole argument: you win a market not by paying less for patients, but by being able to afford more for them than anyone else can.

How it works here

1. Establish both halves

   Lifetime value and acquisition cost, calculated over the same period and the same patient cohort. Mixing timeframes produces a flattering number that is not true.

2. Read the ratio

   Under 3:1 the constraint is usually retention or price, not marketing. Over 5:1 the constraint is usually that you are not spending enough.

3. Improve the numerator first

   Acquisition cost is set largely by an auction you do not control. Lifetime value is set by you. Almost every durable improvement to this ratio comes from the top half.

Questions owners ask

What if my ratio is enormous — say 20:1?

That is rarely a triumph. It usually means a practice living on referrals and word of mouth with no acquisition engine at all, which is comfortable until the referrals slow down. A 20:1 ratio is an instruction to invest, not a reason to celebrate.

How often should I check it?

Quarterly is enough. It moves too slowly to be a monthly number and too fast to be an annual one.

Related

• Lifetime Value (LTV)What one patient is worth across the whole relationship, not the first appointment — treatments, retail and referrals included.
• Customer Acquisition Cost (CAC)What it actually costs you to put one new patient in the chair, once every rand of marketing is counted.
• Payback PeriodHow long it takes a new patient to repay what you spent acquiring them — the number that governs cash flow.
• Front End & Back EndThe first sale versus everything that follows it — and the reason the first sale is the least profitable one you make.