Lifetime Value of a Customer Free Calculator

Q: Should I subtract CAC inside LTV?

Keep them separate. Gross discounted LTV is the asset. Net LTV and LTV:CAC tell you whether acquisition is paying back.

Q: What LTV:CAC ratio is good?

There is no universal number. Many ecommerce and subscription teams use 3:1 as a planning floor, then check payback against cash. Margin and discount rate matter more than a generic benchmark.

What is the lifetime value of a customer?

Most teams still judge growth by how cheaply they can buy a first order. That is the wrong unit. The number that should set your ad bids, your support budget, and whether a “cheap” channel is actually expensive is the lifetime value of a customer — the present value of the profit you expect from the relationship, not the revenue from week one.

How to read every box in the calculator (plain English)

You do not need a finance degree. Think of a small shop — stickers, snacks, whatever — and one regular customer named Sam. The calculator asks simple questions about Sam, then shows how much profit Sam is worth over time. Below is what each field means, with the same friendly example running through the whole page.

Meet Sam and the sticker shop

Sam buys $80 of stickers per order, about four times a year. After paying for the stickers themselves, the shop keeps 40% as profit — that is $128 profit from Sam this year ($80 × 4 × 40%). You spent $60 on ads to get Sam in the door. Out of 100 customers like Sam, about 70 still buy next year. That is the story the default numbers tell.

Inputs — what you type in

Average order value: How much money one visit (or one order) brings in, before costs. Sam spends $80 each time — that is the average order value. If some people spend $50 and others $110, use the middle: total revenue ÷ number of orders.
Orders per year: How many times a happy customer buys in one year. Sam comes back 4 times — birthdays, holidays, random Tuesdays. A customer who buys once and disappears counts as 1. A subscriber who pays monthly counts as 12.
Gross margin %: Of each dollar Sam pays, how much is actually yours after making or buying the product? If a $80 order costs you $48 in stickers and shipping, you keep $32 — that is 40% margin. Do not count rent, salaries, or ads here; those come later. Margin answers: “After the product itself, what is left?”
Annual retention %: Out of 100 customers who bought this year, how many buy again next year? If 70 come back, retention is 70%. The rest drifted away — that is churn. This number moves the lifetime value of a customer more than almost anything else. Better support, faster shipping, and fair returns all nudge it up.
Discount rate %: A dollar next year is worth a little less than a dollar today — like choosing between candy now or candy later. Businesses often use 8–12% here. The calculator uses it so future profit is not counted at full face value. Without it, the tool would pretend money years from now is as good as cash in your pocket today.
Annual spend growth %: Does Sam spend a little more each year — bigger orders, extra add-ons? If Sam stays flat at $80, use 0%. If loyal customers typically upgrade and spend 5% more annually, type 5. Leave at zero when you are not sure; that is the safe default.
Customer acquisition cost (CAC): What did you spend to get Sam? Ads, influencer posts, signup discounts — add it up. If you paid $60 to acquire Sam, that is CAC. Optional, but it unlocks “did we make our money back?” and “how many Sams can we afford to buy?”
Time horizon: How far into the future should we look? 3, 5, or 10 years caps the story at a fixed window — useful for planning. Infinite lets the math run the full relationship (with a standard formula) when retention and margin stay steady.
Include current year (year 0): When on, the calculator counts Sam’s profit this year plus all future years. When off, it only counts starting next year — handy if you already booked this year and want forward-looking value only.

Outputs — what the numbers and charts mean

Discounted LTV: The headline answer: total profit you expect from Sam over the relationship, with future years weighed down slightly by the discount rate. This is the honest lifetime value of a customer — not revenue, not a guess from 1 ÷ churn. For the default sticker-shop inputs, it lands around $352 (your number updates live as you type).
Net LTV (after CAC): Discounted LTV minus what you paid to get Sam. If LTV is $352 and CAC is $60, net LTV is about $292 — the profit left after the ad bill. Negative net LTV means you are paying more to acquire customers than they ever give back. That is a stop sign.
LTV : CAC: How many dollars of lifetime profit you get for each dollar spent acquiring a customer. $352 ÷ $60 ≈ 6× — for every $1 on ads, you expect $6 of profit back over time. Many teams treat 3× as a floor; higher is better, as long as payback is fast enough for your cash flow.
CAC payback: How many years until Sam’s profit covers the $60 you spent. If Sam earns you $128 in year one, payback is under one year — you got your ad money back quickly. Slow payback is risky when ad budgets are tight.
Cash flow by year (chart): A picture of money arriving over time. The filled area is profit each year (after discounting). The line climbing on top is the running total — when it crosses your CAC line mentally, you have paid yourself back. Year 1 is usually the tallest bar; later years shrink as some customers leave.
Retention decay (chart): If 100 Sams start today and 70% stay each year, the line shows how many are still shopping: 100 → 70 → 49 → 34… It is the visual version of “friends who keep coming back to the sticker shop.” Steeper drop = more churn = lower LTV.
LTV vs retention (chart): Same shop, same prices — only retention changes. Watch the curve bend upward as you move from 40% to 90%. That is why a 5-point retention bump can matter more than a flashy new ad creative: the math compounds quietly in your favor.

Sam’s sticker shop — step by step

Sam spends $80 per order and orders 4 times a year → $320 revenue from Sam annually.
At 40% margin, the shop keeps $128 of that as profit this year — that is the “annual margin” line under the results.
You paid $60 in ads to win Sam. So far you are up $68 in year one — but Sam might leave next year, so we do not stop there.
With 70% retention, about 70 of every 100 Sams order again next year, then 70% of those the year after, and so on. The calculator adds up that shrinking stream of profit, discounts future years at 10%, and shows a discounted LTV near $352.
Subtract the $60 CAC → roughly $292 net. LTV:CAC is about 6×. Payback happens in year one because $128 profit exceeds $60 spend.
Now change retention from 70% to 75% in the calculator and watch discounted LTV jump — that is the chart on the right doing the same thing in one glance.

Your business is probably bigger than a sticker shop, but the logic is identical: average ticket × how often they return × what you keep × how long they stay − what you paid to find them. Plug in your best estimates, then refine as you learn.

The problem: first-order math hides churn

Paid acquisition keeps getting noisier. You can “win” a campaign on cost-per-purchase and still lose money if those buyers never come back. Harvard Business Review put the gap plainly: acquiring a new customer is typically five to 25 times more expensive than keeping one you already have (Amy Gallo, HBR, 2014). If you do not know the lifetime value of a customer, you cannot tell whether a 5% lift in retention is worth more than another creative test.

Support is part of that same ledger. Slow answers, missing order status, and “let me escalate that” are not soft issues. They are retention events. Every unresolved ticket is a quiet vote to shop somewhere else next time — which collapses the years of margin your model assumed.

The formula this calculator uses (and why it is more accurate)

A popular shortcut is average order value × orders per year × expected years. Expected years is often written as 1 ÷ churn. That shortcut is easy — and it overstates the case. Sunil Gupta and Donald Lehmann showed that treating “expected lifetime” as a fixed horizon generally overestimates customer value, sometimes by a wide margin (Gupta, Lehmann et al., Journal of Service Research, 2006; see also Gupta & Lehmann, “Customers as Assets,” 2003).

“CLV is generally defined as the present value of all future profits obtained from a customer over his or her life of relationship with a firm.”
— Gupta, Lehmann, and colleagues, Modeling Customer Lifetime Value

When margin and retention are reasonably stable, that present-value sum collapses to a closed form. With annual contribution margin m, retention r, and discount rate i:

LTV = m × (1 + i) / (1 + i − r)

That version includes the current year. Future years only are m × r / (1 + i − r). If spend grows at rate g, replace r with r(1 + g) — provided the series still converges. Harvard Business School’s marketing toolkit uses the same asset logic: acquire, maximize, and retain (Steenburgh & Avery, HBS note). Darden’s 2024 technical note walks through three empirical methods, from individual purchase histories to this constant-retention case (Zhang, Whitler & Venkatesan).

Use contribution margin, not revenue. Revenue LTV looks impressive and then fails when you compare it to CAC. Keep the discount rate honest (often 8–12%). And remember the model assumes a fairly constant retention rate. Heterogeneous “buy-till-you-die” models (Fader, Hardie & Lee) are better when you have individual transaction logs — this tool is the right starting point when you have store-level averages.

What the research says retention is worth

Frederick Reichheld’s work at Bain is still the citation boards reach for. In Loyalty Rules! he wrote:

“An increase in customer retention rates of 5 percent increases profits by 25 percent to 95 percent.”
— Frederick Reichheld, Bain & Company, Loyalty Rules!, chapter 1

That range is not a law of nature. It came from dissecting life-cycle economics across industries: acquisition is front-loaded, serving a known customer gets cheaper, and loyal buyers tend to buy more and refer others (Bain, “Prescription for Cutting Costs”). The calculator’s “LTV vs retention” chart is there so you can see your 5-point move, not a generic slide.

Vanguard is a useful case of choosing customers who will stay. Jack Brennan’s team turned away a $40 million institutional subscription when they judged the money would churn and raise costs for everyone else — a retention decision dressed as an acquisition “no” (same Bain brief). Ecommerce rhymes with that: a discount code that attracts one-and-done shoppers can lower blended LTV even while it “wins” ROAS.

How ChatInCart lifts the inputs you just typed — with numbers

Retention r is not a finance abstraction. It is whether someone gets a shipping update at 11 p.m., whether the return policy is explained without ticket ping-pong, and whether the same answer appears on your site, in chat, and in email. ChatInCart is an AI customer service agent you train on your website and docs, then embed so shoppers get those answers instantly — 24/7.

Support quality shows up directly in the retention slider above. Bain found that a 5-point increase in retention raises profits 25% to 95% across industries (Reichheld, Bain). On this calculator, moving retention from 70% to 75% lifts discounted LTV from about $352 to $402 — roughly $50 more profit per customer with the same order value and margin. That is the dollar value of keeping people who would otherwise churn after one bad support experience.

AI customer service is how operators actually move that number:

Vodafone +20% NPS and up to 50% better first-time resolution on billing after GenAI on its virtual agent (CX Today, 2024) — fewer angry customers leaving for good.
Bain +10–15 NPS points when banks fixed high-impact service interactions (Bain loyalty brief) — the same interactions an AI agent handles at scale.
McKinsey +15–28 NPS from deliberate delight moments in banking, insurance, and tourism (McKinsey, 2023) — a correct first reply is one of those moments.
Industry surveys link a 10-point NPS gain to ~6–7% revenue growth (Desk365 roundup), which flows back into higher LTV on this page.

ChatInCart maps onto the model in three places: instant answers protect retention r; fewer repetitive tickets free humans for upsell conversations (growth g); and integrations let the agent look up orders and open tickets in one thread instead of three. Measure NPS with our NPS calculator, then model retention here. There is a free tier to deploy before you change another ad bid.

For more on how teams run support, see the ChatInCart blog. Raise retention five points in the calculator and look at net LTV again — that delta is the budget conversation worth having.

Common questions

Where do I find these numbers in real life?

Average order value and order frequency come from your store or billing reports. Margin from your finance team or unit economics sheet. Retention from cohort reports (same customers buying again 12 months later). CAC from ad spend ÷ new customers in that period. Rough guesses are fine to start — directionally correct beats perfectly missing.

Is LTV the same as CLV?

In practice, yes. Customer lifetime value (CLV) is the academic name; LTV is the operator’s name. Both should be discounted profit, not undiscounted revenue.

Should I subtract CAC inside LTV?

Keep them separate. Gross (discounted) LTV is the asset. Net LTV and LTV:CAC tell you whether acquisition is paying back. Mixing CAC into the LTV formula makes it harder to compare channels.

What LTV:CAC ratio is “good”?

There is no universal number. Many subscription and ecommerce teams use 3:1 as a planning floor, then sanity-check payback against cash. Your margin and discount rate matter more than a generic benchmark tweet.