Why customer lifetime value matters
Customer lifetime value (CLV or LTV) is the total gross profit a single customer is expected to generate over the lifetime of your relationship. It answers the most important marketing question in any business: how much can I afford to spend to acquire a new customer? If CLV is $600 and you spend $200 on each acquisition, you have a healthy 3:1 LTV:CAC ratio. If you are spending $500 to acquire a $600 customer, you are running on thin ice.
The calculator supports two common models. For subscription businesses, the formula is CLV = ARPU × Gross Margin / Monthly Churn Rate. For repeat-purchase businesses, the formula is CLV = Average Order × Purchases per Year × Years Active × Gross Margin. Both are simplifications; they capture 90% of the value of CLV analysis in a one-page calculator.
Subscription LTV: churn is the denominator
In subscription, monthly churn rate is the single biggest lever on LTV. Cut churn in half and LTV doubles. Monthly ARPU of $50, 80% gross margin, 5% monthly churn = $800 LTV. Same ARPU and margin, 2.5% churn = $1,600 LTV. That is why growth-stage SaaS companies obsess over churn — it is a multiplier on everything.
The "1/churn" term in the formula is the average lifetime in months. At 5% monthly churn, the average customer stays 20 months. At 2% churn, 50 months. See our churn calculator for benchmarks on what a good churn rate actually looks like for your segment.
Repeat-purchase LTV: frequency and tenure
For ecommerce and retail, LTV is driven by two numbers most businesses do not track: purchases per year and years active. A customer who buys twice a year for three years is worth six times one who buys once and never returns. If your repeat-purchase rate is weak, invest in email, loyalty programs, and product assortment that drives repeat visits — almost always cheaper than acquiring new buyers.
Most DTC ecommerce brands have an average of 1.3–1.8 purchases per year from customers who make at least one purchase. Subscription boxes and consumables can hit 4–8+. Rough tenure is typically 18–36 months depending on category.
LTV:CAC ratio — the number investors obsess over
Customer acquisition cost (CAC) is the total marketing + sales cost to acquire one new customer. The LTV:CAC ratio is the headline efficiency metric. Rules of thumb for different business types:
- < 1:1 — you lose money on every customer. Fix immediately.
- 1:1 to 2:1 — marginal. Works only if you have operational leverage to improve over time.
- 3:1 or better — healthy. Growth investors expect this.
- 5:1+ — strong. Often means you are under-investing in marketing and could grow faster.
Payback period is as important as the ratio
A 5:1 LTV:CAC looks great — but if it takes 36 months to recover the CAC, the business starves for cash while it grows. Payback period is CAC / Monthly Gross Profit per Customer. Healthy SaaS businesses recover CAC in under 12 months; ecommerce and DTC aim for 3–6 months because the competition for shelf space and ad inventory is fierce.
What lowers LTV without you noticing
- Discounts at acquisition. A 50%-off first-month promo lowers year-one revenue per customer meaningfully and often those customers churn at higher rates.
- Free shipping thresholds that erode margin. $35 AOV with free shipping at $50 can raise AOV but cut margin.
- Non-engaged customers. Customers who never activate the product or service churn fast. Time-to-first-value matters more than first-month revenue.
- Support cost on the long tail. If the bottom 20% of customers produce 60% of support tickets, their effective margin is much lower than headline.
LTV by cohort tells the real story
A single aggregate LTV number is dangerous. Split customers by acquisition cohort (paid vs organic, channel, plan), and you will usually find a 3–5× spread between your best and worst cohorts. Investing more in the channels that produce 2–3× LTV customers and cutting channels that produce 0.5× LTV customers is the single highest-leverage marketing decision most businesses can make. Pair the LTV calculator with the ROI calculator to evaluate individual campaigns.
Use discount rate for long-lived customers?
If customer lifetimes are very long (5+ years), a future dollar is worth less than a current dollar, and technically CLV should be discounted. For small businesses, this is usually noise — the math accuracy is better spent on improving churn or raising prices than on applying a discount rate. Only bother if you are making capital allocation decisions on a 10-year horizon.
Grow LTV, not just revenue
Three levers to grow LTV, in order of ease: improve retention (cut churn or increase repeat purchases), raise prices on existing customers, expand use cases with upsells or cross-sells. Acquiring new customers is the most expensive lever and most businesses over-index on it. The pricing calculator helps you model price increases on existing customer base without losing them.