Customer lifetime value calculator
Lifetime value (LTV) and customer acquisition cost (CAC) only mean anything next to each other, a low CAC on a customer worth even less is a losing business, and a high CAC on a customer worth far more is a growth engine. This unit economics calculator runs both at once.
CAC
$300
LTV
$1225
LTV : CAC
4.1×
CAC payback
8.2 mo
Every dollar spent acquiring a customer returns about $4.08 in gross-margin value over that customer's lifetime, and it takes about 8.2 months to earn the acquisition cost back.
CAC and LTV formulas
Average customer lifetime, in months, is simply 1 ÷ monthly churn rate, a 3% monthly churn rate implies an average lifetime of about 33 months. That figure then multiplies against monthly gross-margin revenue per customer to produce lifetime value. Churned MRR ÷ starting MRR from the MRR calculator is the same churn rate, if that's where the raw numbers already live.
A worked example
A SaaS business spends $12,000 a month on sales and marketing and acquires 40 new customers a month. CAC: $12,000 ÷ 40 = $300 per customer.
Each customer pays $49 a month, at a 75% gross margin: $36.75 in gross-margin revenue per customer per month. Monthly churn is 3%, implying an average lifetime of 1 ÷ 0.03 = 33.3 months. LTV: $36.75 × 33.3 = $1,224.
LTV : CAC ratio: $1,224 ÷ $300 = 4.1×, comfortably above the 3:1 healthy benchmark. CAC payback: $300 ÷ $36.75 = 8.2 months to recover the acquisition cost.
What's included in CAC
Paid search, social, display, the most obviously variable part of acquisition cost.
The most commonly missed line item. If a sales team exists to close new customers, its cost belongs in CAC, even though it doesn't feel as variable as ad spend.
CRM, email platforms, analytics tools, and ad management software used specifically for acquisition.
Design, copywriting, video production. Any cost directly producing acquisition-facing assets.
A real acquisition cost, even though it's paid to a customer or partner rather than a media platform.
Blended CAC vs. paid CAC
The CAC formula above answers a question that has two different honest answers, depending on which customers and which spend go into it.
Blended CAC divides all sales and marketing spend by every new customer, including organic search, referral, and word-of-mouth arrivals that cost nothing directly to acquire. Paid CAC divides only paid spend by the customers attributed to paid channels specifically. Blended is always lower, since organic customers pull the average down without adding to the numerator.
A business acquiring 2,000 customers a month. 1,200 from paid channels, 800 from organic and referral, on $84,000 of paid spend has a blended CAC of $84,000 ÷ 2,000 = $42, but a paid CAC of $84,000 ÷ 1,200 = $70, a 67% gap between the two numbers describing the exact same month.
Both are legitimate; they answer different questions. Blended CAC is the honest company-wide number. What growth actually costs across every source. Paid CAC is the actionable one. Whether the ad spend itself is working, independent of how much organic traffic happens to be carrying the average. Reporting only the blended figure while organic growth is strong can mask paid channels that are quietly becoming unprofitable; comparing your blended number against someone else's paid number is one of the more common apples-to-oranges mistakes in this space.
Why LTV uses gross margin, not revenue
Revenue per customer overstates their real value, because it ignores what it costs to actually serve them. Hosting, support, payment processing. This is the same principle behind contribution margin: the number that matters is what's left after variable costs, not the top-line figure. A $49/month customer at 75% gross margin is worth $36.75/month to the business, not $49, and that's the number that belongs in an LTV calculation used to judge whether acquisition spend is worth it.
LTV:CAC by acquisition channel
A single blended LTV:CAC ratio can look perfectly healthy while hiding a wide spread underneath it. One channel performing excellently, another barely breaking even, averaged together into a number that doesn't point anywhere useful. Calculating LTV and CAC separately by channel, not just splitting CAC into blended versus paid, is what actually reveals where to spend more and where to pull back.
A business acquiring 60 customers a month through referral at $1,600 CAC with $8,000 LTV, a 5.0:1 ratio , and 40 customers through paid search at $2,400 CAC with $6,000 LTV (a 2.5:1 ratio) shows a blended ratio of 3.75:1 across the business as a whole. That blended number is comfortably healthy and would raise no alarms on its own, but it obscures a paid-search channel running at exactly the widely-cited minimum and a referral channel performing twice as well. Reallocating spend toward referral and away from paid search (impossible to see from the blended number alone) is the actual decision this breakdown enables.
Healthy LTV:CAC benchmarks
These are general SaaS benchmarks, the right ratio for your business depends on growth stage, funding, and how much cash flexibility you have.
Below 1:1: losing money on every customer, before accounting for fixed costs at all, not sustainable at any volume.
1:1 to 3:1: marginal to acceptable, common at early-stage companies still refining their acquisition channels.
3:1 or better: the widely cited healthy target, enough margin above acquisition cost to fund operations and growth. Worth treating this as a floor rather than an aspiration, though: recent industry data puts the median for private B2B SaaS companies closer to 3.6:1, meaning a ratio right at 3:1 is already somewhat below typical, not comfortably ahead of it.
Well above 5:1: worth a second look. This can mean excellent unit economics, but it can also mean under-investment in growth, if the ratio is this favorable, spending more on acquisition would likely still be profitable.
The 3:1 benchmark traces back to venture capitalist David Skok, who popularized it around 2010 from observing mature, steady-state SaaS companies, it's a reasonable default, not a universal law. It also varies by capital structure: a bootstrapped business generally needs 4:1 or better to fund growth from its own cash, a VC-backed early-stage company can operate at a lower 1.5:1-2:1 with an improving trend, and businesses outside SaaS run differently entirely. DTC e-commerce commonly sits at 1.5:1-3:1, marketplaces target a 3:1 floor. For the full set of SaaS metrics reframed around self-funded cash constraints instead of investor benchmarks, see the bootstrapped-founder metrics guide.
Calculating your own break-even LTV:CAC ratio
Rather than borrowing a generic 3:1 target, the ratio your specific business actually needs to break even can be calculated directly from your own cost structure.
A business where sales and marketing make up 40% of total operating costs needs a minimum LTV:CAC of 1 ÷ 0.40 = 2.5:1 just to break even overall. Below that, the business loses money even if each individual customer looks profitable on paper, since sales and marketing spend is eating too large a share of the cost base. A business where sales and marketing is a leaner 20% of costs needs only 1 ÷ 0.20 = 5:1 as its floor. This is a more precise target than the generic 3:1 rule, since it's built from the specific cost structure of the business being measured, not an industry-wide average.
CAC payback period benchmarks
Payback period matters separately from LTV:CAC because it measures cash timing, not just eventual profitability, a 4:1 LTV:CAC ratio with a 24-month payback still ties up cash for two years per customer, which matters enormously for a business watching its runway. Under 12 months is generally healthy for SaaS; under 6 months is strong; over 18 months warrants a closer look at whether acquisition spend is scaling faster than the cash to fund it. This CAC payback timeline is one half of what "break-even" actually means for a SaaS business. See the worked example distinguishing it from company-wide break-even.
CAC benchmarks by business type
Absolute CAC figures vary enormously. What matters more is the ratio to LTV covered above, but a rough sense of typical dollar ranges helps sanity-check a number in isolation.
SMB SaaS: roughly $100-$300 per customer, reflecting shorter sales cycles and smaller deal sizes.
Mid-market SaaS: roughly $500-$1,500, as sales cycles lengthen and deals increasingly involve a sales team rather than self-serve signup.
Enterprise SaaS: often $2,000 and up, sometimes well beyond, given long sales cycles, multiple stakeholders, and significant sales team involvement per deal.
DTC e-commerce: commonly $50-$200, though this varies heavily by category and how competitive paid social and search are for that specific product.
How churn drives lifetime value
Because average lifetime is 1 ÷ churn rate, small changes in churn move LTV dramatically. Dropping monthly churn from 5% to 3% doesn't just improve retention , it takes average lifetime from 20 months to 33.3 months, a 67% increase in LTV from the same ARPU and margin.
This is why retention work often has a larger effect on unit economics than acquisition efficiency does, a churn improvement compounds into every customer already acquired, while a CAC improvement only affects new customers going forward.
A 2-point drop in monthly churn does more for lifetime value than most CAC-reduction campaigns ever will.
Historic vs. predictive LTV
The churn-based formula this calculator uses is a predictive approach, it projects forward from a current churn rate to estimate what a customer will be worth. The alternative is historic LTV: summing what a specific cohort of customers has actually spent to date, no projection involved.
Historic LTV is simple and fully auditable. Every dollar in it already happened, but it understates future value for a growing business, since a cohort measured today hasn't finished generating revenue yet, and it's prone to survivorship bias: a cohort measured a year in only includes the customers who stuck around, quietly excluding everyone who already churned out. Predictive LTV, the churn-rate approach used throughout this page, corrects for that by projecting the full expected lifetime rather than measuring only what's happened so far, the right choice for forward-looking decisions like setting a CAC budget, while historic LTV remains useful for auditing what a past cohort actually delivered.
Should LTV be discounted to present value?
The formula on this page treats a dollar of revenue in month 30 the same as a dollar today, which slightly overstates LTV for a long-lived customer relationship, a dollar received two and a half years from now is worth less than one in hand, the same time-value-of-money principle behind any financial valuation. For most small and mid-size businesses making pricing and CAC-budget decisions, this simplification is fine, the churn rate itself is already an estimate, and adding a discount rate on top rarely changes the decision. It matters more for longer customer lifetimes (multi-year enterprise contracts) or when LTV feeds directly into a formal valuation, where discounting future cash flows at a reasonable rate (commonly 8-12% annually for this kind of projection) is the more defensible approach.
Unit economics and your break-even point
Break-even and CVP analysis assume a stable price and variable cost per unit. They don't account for what it costs to win each customer in the first place. A business can be well above its break-even point on a per-sale basis and still be losing money overall if CAC is high enough relative to LTV. Unit economics is the layer that catches what break-even math alone doesn't see.
How to improve your unit economics
As the compounding effect above shows, a churn improvement often moves LTV more than an equivalent CAC reduction moves the ratio.
Every dollar of additional ARPU flows through gross margin directly into LTV. See the contribution margin and pricing pages for the levers behind this.
CAC is rarely uniform across channels. Calculating it separately by channel, the same way contribution margin can be tracked by sales channel, often reveals one channel quietly dragging the blended average down.
A faster path from lead to paying customer reduces the sales-cost portion of CAC without touching ad spend at all.
A unit economics health check
Run through these before trusting a CAC or LTV figure.
Not just ad spend. Salaries, commissions, and tools too.
The cost of serving each customer has been subtracted out.
Based on actual recent cohort data, not an early-days rate that's since drifted.
Comparing this month's CAC against a churn rate calculated a year ago produces a misleading ratio.
Payback period vs. LTV:CAC ratio, which matters more?
They can point in different directions, and which one to weight more heavily depends on what constraint the business is actually facing. LTV:CAC ratio measures eventual profitability, a good ratio means acquisition spend pays off handsomely over a customer's full lifetime. CAC payback measures cash timing, how long that payoff takes to actually arrive. A business with plenty of runway and a strong LTV:CAC ratio can comfortably tolerate a longer payback period, since it has the cash cushion to wait for the return. A business watching its runway closely should weight payback period more heavily even with an excellent ratio, since a 24-month payback ties up cash for two years per customer regardless of how good the eventual multiple looks on paper, the two metrics are answering "is this worth it" and "can we afford to wait for it" respectively, and a healthy business needs a satisfactory answer to both, not just one.
Common CAC and LTV mistakes
Ad spend feels variable and obviously belongs in CAC; a salaried sales team doing the same acquisition work often gets left out simply because it doesn't feel as directly tied to a specific customer.
Skipping the margin adjustment overstates lifetime value by exactly the amount it costs to serve each customer. See the section above on why LTV uses gross margin, not revenue.
A blended LTV:CAC ratio can look healthy while one specific channel is quietly unprofitable underneath it. Calculating CAC and LTV per channel surfaces problems a single company-wide number hides.
Churn drifts, sometimes quickly. An LTV calculation built on a churn figure from two quarters ago can meaningfully overstate or understate current lifetime value, especially after a pricing change or a shift in the customer base.
What this doesn't account for
This calculator assumes a steady blended CAC and a constant churn rate. Real businesses usually see CAC rise as a channel saturates, and churn that varies by customer cohort or acquisition source. Treat the output as a planning baseline, and where possible calculate CAC and LTV separately by channel or cohort rather than relying on one blended figure for every decision.
Frequently asked questions
3:1 is the commonly cited healthy benchmark. Every dollar spent acquiring a customer returns roughly three dollars in gross-margin value. Below 1:1 means you're losing money on every customer regardless of how many you acquire. Above roughly 5:1 can actually signal under-investment in growth, since it suggests spending more on acquisition would still be profitable.
Usually a cohort-matching problem. Comparing this quarter's CAC against a churn rate measured a year ago, or blending a high-churn early-tenure cohort with a mature, stable one, both produce misleading numbers. Calculate CAC and churn from the same cohort and the same time window, and calculate the ratio separately by acquisition channel rather than relying on one blended company-wide figure.
Under 12 months is generally considered healthy for a SaaS business, and under 6 months is strong. Longer payback periods aren't automatically bad, but they mean more cash is tied up before a customer becomes profitable, which matters more for a business with limited runway than one that's well-funded.
Because revenue overstates what a customer is actually worth. If it costs money to serve each customer (hosting, support, payment processing) that cost has to come out before the number reflects real value, the same way contribution margin does for a break-even calculation.
All sales and marketing spend that led to those new customers. Ad spend, sales salaries and commissions, marketing tools and software, content and creative production, and any referral or affiliate payouts. Leaving out sales team salaries because they feel like a fixed cost is one of the most common ways CAC gets understated.
Lifetime value depends on churn, with 0% monthly churn, a customer's expected lifetime is mathematically undefined (infinite), which is shown as a blank rather than a misleadingly huge number. Enter a realistic churn rate above zero to see a usable LTV figure.
The CAC side works identically. LTV needs adjusting, instead of churn-based lifetime, use average number of repeat purchases per customer and average order gross margin, then multiply the two, rather than the churn formula this calculator uses.
Blended CAC divides all spend by every new customer, including free organic and referral arrivals. Paid CAC divides only paid spend by paid-attributed customers, and is always higher. Both are legitimate; report both rather than letting a strong organic month quietly flatter the number investors or a team sees.
Predictive LTV (the churn-based formula this calculator uses) for forward-looking decisions like setting a CAC budget. Historic LTV, summing what a cohort has actually spent, is useful for auditing past performance but understates future value for a growing business and is prone to survivorship bias.
For most small and mid-size businesses, no, the churn-rate estimate already carries more uncertainty than a discount rate would meaningfully correct for. It's worth doing for long enterprise contract lifetimes or when LTV feeds directly into a formal company valuation.
Calculate your own CAC and LTV above, free, or see how they connect to your break-even point and runway.