Unit economics is the profit or loss a business makes on a single unit of what it sells, whether that unit is an order, a customer or a subscription month. If the unit economics are negative, growing faster only loses money faster. Investors ask about unit economics first, but the concept matters just as much to a bootstrapped MSME deciding whether to spend on online ads, open a new delivery zone or launch a subscription plan. This guide explains contribution margin levels, customer acquisition cost (CAC), lifetime value (LTV), the LTV to CAC ratio and payback period, with full worked examples in rupees and the levers that fix weak numbers.
What Unit Economics Means
Unit economics asks a simple question: when we sell one more unit, do we make money, and how much? It deliberately ignores fixed overheads like head office rent and founder salaries, because those do not change with one more sale. The answer is then compared with the cost of acquiring the customer who buys that unit.
Choosing the right unit
- Per order: D2C brands, restaurants, e-commerce sellers
- Per customer: businesses with repeat purchases, where lifetime value matters more than one order
- Per subscription month: SaaS, tiffin services, gyms, maintenance contracts
- Per store or branch: retail chains and franchises, where each location is a unit
Contribution Margin Levels: CM1, CM2, CM3
Many Indian startups and D2C brands break contribution into three levels:
- CM1 = Net revenue minus cost of goods (product cost)
- CM2 = CM1 minus fulfilment costs (shipping, packaging, payment gateway fees, returns and RTO losses, warehousing per order)
- CM3 = CM2 minus marketing cost per order
Net revenue should be after discounts and excluding GST. CM2 is the most honest measure of whether an order makes money before marketing. CM3 shows whether it still makes money after the cost of getting that order.
Worked Example 1: A D2C Skincare Brand
A hypothetical Bengaluru skincare brand sells through its own website. Its average order value is ₹800 after discounts, excluding GST.
| Line item per order | ₹ | % of revenue |
|---|---|---|
| Net revenue | 800 | 100% |
| Product cost (COGS) | (240) | 30% |
| CM1 | 560 | 70% |
| Shipping | (70) | 8.8% |
| Packaging | (25) | 3.1% |
| Payment gateway (2%) | (16) | 2.0% |
| Returns and RTO cost (averaged) | (40) | 5.0% |
| CM2 | 409 | 51.1% |
So far, healthy. Now add marketing.
Customer acquisition cost
CAC = Total sales and marketing spend to acquire new customers / Number of new customers acquired
The brand spent ₹12 lakh in a month on ads, influencer fees and agency retainer, and acquired 1,000 new customers. CAC = ₹1,200. On the first order alone, CM3 = 409 minus 1,200 = minus ₹791. Every new customer loses money on the first order. Whether that is acceptable depends on repeat purchases.
Lifetime value
LTV (contribution basis) = CM2 per order x Average number of orders per customer over their lifetime
The brand's data shows customers place 2.5 orders on average over 18 months. LTV = 409 x 2.5 = ₹1,022.50.
- LTV to CAC ratio = 1,022.50 / 1,200 = 0.85
- Payback: the brand needs 1,200 / 409 = 2.93 orders to recover CAC, but the average customer places only 2.5
The business loses about ₹177 per customer over the customer's life. Spending more on ads would deepen losses. Using revenue instead of contribution for LTV (₹800 x 2.5 = ₹2,000) would have made the ratio look like 1.67, a dangerous illusion.
Fixing Weak Unit Economics: Scenario Table
Here is how the four main levers change the picture. Each row builds on the previous one.
| Scenario | AOV (₹) | CM2 (₹) | Orders per customer | LTV (₹) | CAC (₹) | LTV / CAC |
|---|---|---|---|---|---|---|
| Current | 800 | 409 | 2.5 | 1,022 | 1,200 | 0.85 |
| Raise AOV with bundles | 1,000 | 545 | 2.5 | 1,362 | 1,200 | 1.14 |
| Plus better retention | 1,000 | 545 | 3.5 | 1,907 | 1,200 | 1.59 |
| Plus referrals and organic lower CAC | 1,000 | 545 | 3.5 | 1,907 | 900 | 2.12 |
| Plus lower RTO via prepaid nudges | 1,000 | 575 | 3.5 | 2,012 | 900 | 2.24 |
The AOV row assumes COGS rises proportionally to ₹300 and fulfilment rises by ₹4 (higher gateway fee), so CM2 = 1,000 minus 300 minus 155 = ₹545. The last row assumes returns and RTO cost falls by ₹30 per order. No single lever fixes the business; the combination does. A common benchmark cited by investors is an LTV to CAC ratio of 3 or more, with CAC payback within 12 months, but appropriate targets vary by category and capital availability.
Worked Example 2: A Subscription Tiffin Service
For subscription businesses, LTV is easier to calculate using churn.
- Monthly subscription: ₹3,000 (excluding GST)
- Food and packaging cost: ₹1,500 a month
- Delivery cost: ₹450 a month
- Monthly contribution: ₹3,000 minus ₹1,500 minus ₹450 = ₹1,050
- Monthly churn: 10% of subscribers cancel each month
- Average customer lifetime = 1 / churn = 1 / 0.10 = 10 months
- LTV = ₹1,050 x 10 = ₹10,500
- CAC (flyers, society activations, referral bonus): ₹2,000
- LTV to CAC = 10,500 / 2,000 = 5.25
- Payback = 2,000 / 1,050 = 1.9 months
Strong unit economics. The risk to watch is churn: if churn rises to 20%, lifetime halves to 5 months, LTV falls to ₹5,250 and the ratio drops to 2.6. For a subscription business, a 5-point change in monthly churn matters more than a 10% change in price.
How to Calculate CAC Correctly
CAC is the most frequently understated number in small business plans. Include:
- Paid ad spend across all platforms
- Agency and freelancer fees for marketing
- Influencer and affiliate payouts
- Salaries and incentives of sales and marketing staff, prorated to new customer acquisition
- Discounts and free samples given to first-time buyers (or treat them as revenue reduction, but consistently)
- Marketplace or lead-generation platform fees for new customers
Blended vs paid CAC
Blended CAC divides all acquisition spend by all new customers, including those who came organically. Paid CAC divides paid spend only by customers attributable to paid channels. Blended CAC flatters the numbers when organic growth is strong; paid CAC tells you whether scaling ads will work. Track both.
Unit Economics for Traditional MSMEs
Unit economics is not only for startups. A few examples of how it applies in conventional businesses:
- Distributor: unit = retailer account. Contribution per retailer per month after scheme costs and delivery, versus the salesperson cost to open and serve that account.
- Restaurant: unit = cover or order. Food cost, packaging and aggregator commission per delivery order versus dine-in.
- Retail chain: unit = store. Store-level EBITDA after rent and staff, and payback period on fit-out capex.
- B2B manufacturer: unit = customer. Contribution per customer per year net of freight, credit cost and service visits, versus the cost of the sales effort to win them.
Once you know contribution per unit, you can link it to fixed costs through break-even analysis.
Common Unit Economics Mistakes
- Using revenue instead of contribution for LTV. This inflates LTV by two to three times.
- Assuming retention you have not observed. Use actual cohort data. A new business should be conservative, for example counting only 12 to 18 months of customer life.
- Ignoring returns and cash on delivery failures. RTO can be a significant share of orders in some categories and cities.
- Leaving out GST correctly. Revenue and costs should both exclude GST where input credit is available.
- Averaging away the problem. One profitable channel can hide another that loses money. Calculate unit economics by channel, city and product.
- Not including the cost of capital. If payback is 18 months, you need to fund CAC for 18 months, often with borrowed money.
Cohort Analysis: The Data Behind LTV
A cohort is a group of customers acquired in the same month. Track what percentage of each cohort orders again in month 2, month 3 and so on, and the cumulative contribution per customer. A simple cohort table looks like this (hypothetical):
| Cohort | Customers | Repeat by month 3 | Repeat by month 6 | Cumulative CM2 per customer by month 6 (₹) |
|---|---|---|---|---|
| January | 900 | 28% | 41% | 690 |
| February | 1,050 | 31% | 44% | 720 |
| March | 1,200 | 35% | 48% | 760 |
Improving cohorts mean retention efforts are working. Declining cohorts often mean newer customers are coming from lower-quality channels, even if CAC looks unchanged.
Unit Economics Review Checklist
- Define the unit (order, customer, subscription, store)
- Calculate CM1, CM2, CM3 by product and channel
- Compute blended and paid CAC monthly
- Build monthly cohorts and measure repeat rates
- Calculate LTV on contribution, not revenue
- Track LTV to CAC and payback months
- Run sensitivity on AOV, churn and CAC
- Review before increasing marketing budgets
Getting Reliable Numbers
Unit economics depend on accurate costs per order and revenue per customer. Fininvo ERP's sales analytics with drill-down by product and customer and cost centre accounting help you separate fulfilment and marketing costs from overheads. See pricing. This article is general information, not financial or investment advice.
Frequently Asked Questions
What is a good LTV to CAC ratio?
A ratio of 3 or more is a widely quoted benchmark, but the right target depends on margins, payback period and your access to capital. A ratio below 1 means each customer loses money over their lifetime.
What is the difference between contribution margin and gross margin?
Gross margin deducts only cost of goods. Contribution margin also deducts other variable costs such as shipping, packaging, payment fees and commissions, and sometimes marketing.
How do I calculate LTV with limited data?
Use observed repeat rates for your oldest cohorts and cap customer life conservatively, for example at 12 months. Update the estimate monthly as data builds up.
Should founder salaries be included in CAC?
If founders spend significant time on sales, include a fair share of their cost. Otherwise CAC looks artificially low and breaks when you hire a sales team.
Can a business with negative unit economics succeed?
Only if there is a clear, evidence-based path to positive unit economics, such as proven repeat purchase growth or falling fulfilment costs with scale. Hoping scale alone will fix it is risky.
Share this article
Ready to automate your business?
Start your 14-day free trial and experience the power of unified ERP, HR, and Payroll.
Start Free Trial