About this tool
CAC is the average cost to acquire one new customer, including all sales and marketing spend. CAC payback is how many months until that customer's gross profit recoups the CAC. Healthy SaaS: payback under 12 months. World-class: under 6.
The textbook fully-loaded CAC includes: sales rep base + commission, BDR salaries, marketing salaries, ad spend (Google, LinkedIn, Meta), content production, events, sales tools (Salesforce, Outreach, ZoomInfo), agency fees, and a fair allocation of marketing leadership. The 2026 SaaS benchmark for blended CAC at the median SMB company sits near $1,450 and rises to $11,000+ for mid-market and $35,000+ for enterprise deals. CAC payback under 12 months remains the canonical SaaS health line set by Bessemer Venture Partners; payback over 24 months historically correlates with capital crunches in downturns.
How it works
Enter total sales and marketing spend over a period (typically a quarter), the new customers acquired in that period, average MRR per customer, and gross margin. The calculator returns CAC, payback months, and LTV/CAC ratio.
Worked example: a B2B SaaS spent $750,000 on sales and marketing last quarter and signed 150 net new customers paying $300/mo average MRR at 78% gross margin. CAC = $750,000 / 150 = $5,000. Payback = $5,000 / ($300 x 0.78) = $5,000 / $234 = 21.4 months. That fails the 12-month line: the team needs to either compress CAC (better targeting, less paid spend) or raise ACV (move upmarket) to clear the bar.
How to use the CAC Calculator
The CAC Calculator is a browser-based tool that runs entirely on your device. Inputs you enter never reach a server - all calculations happen client-side in JavaScript. This means:
- Privacy: nothing is logged, sent, or stored by 3Tej. Inputs disappear when you close the tab.
- Speed: results update as you type. No network round trip.
- Offline use: once the page is cached, it works without internet.
- No signup: no account, no email, no rate limits.
Step by step
- Enter your inputs in the form above. Each field is labeled with its unit (currency, percent, kg, etc.) and the expected range.
- Read the result as it updates. The number reflects the formula commonly accepted in CAC-related calculations.
- Adjust to see sensitivity: change one input at a time and watch how the output moves. This is the fastest way to understand which variable matters most.
- Copy or screenshot the result for later reference. The page state persists for the session if your browser allows it.
When you would use this
- Quick estimates: when you need a number now and don't want to open a spreadsheet.
- Sensitivity analysis: testing how a result changes as inputs vary, before committing to a real-world decision.
- Comparison: running the same calculation with different inputs to compare options side by side.
- Learning: building intuition for how the underlying math behaves.
- Documentation: capturing a snapshot of inputs and outputs at a point in time.
The formula explained
This calculator uses the following formula:
CAC = (sales + marketing) / new_customers; Payback = CAC / (avg_MRR × gross_margin)
The reason this formula works is rooted in the underlying physics, finance, or biology of the problem. Behind every calculator is a published, peer-reviewed equation or a widely accepted convention. We do not invent formulas; we apply standard ones from textbooks, government tables, professional bodies, and academic literature.
If you are curious about the math, the simplest way to verify is to plug in two known numbers and compare against a known result. The calculator should match published examples to within rounding precision.
Frequently asked questions
What counts as 'sales spend'?
Sales team salaries + commissions + tools (CRM, prospecting). Don't include account management for existing customers.
Blended vs paid CAC?
Blended: all customers (including organic). Paid: only marketing-attributed. Investors usually want blended.
Why does payback matter more than CAC?
CAC alone ignores the value generated. A $1,000 CAC on a $200/mo customer is great; on a $10/mo customer, terrible.
CAC ratio?
Some VCs use CAC ratio: net new ARR / sales+marketing. >1 means efficient growth. <1 burns cash.
What is a good LTV:CAC ratio for SaaS?
The SaaS rule of thumb is 3:1 minimum, with 4:1 to 5:1 considered healthy and 6:1+ flagged as under-investment in growth. 2026 OpenView and Bessemer benchmarks show median SMB SaaS at 3.2:1, mid-market at 4.1:1, and enterprise at 5.5:1, where longer contracts pull LTV up.
How long should CAC payback take?
Healthy SaaS payback is under 12 months, world-class is under 6, and anything over 18 months signals capital inefficiency. The 2025 ChartMogul benchmark shows median 14 months for sub-$10M ARR companies and 18 months for $10M-100M ARR; product-led growth companies skew below 9 months.
Is the CAC Calculator accurate?
The CAC Calculator applies the standard formula for cac. Accuracy is limited only by your input precision. For decisions with material consequences, use the result as a starting point and verify with a qualified professional or the relevant official source.
Is the CAC Calculator free?
Yes. 100% free, no signup, no payment, no API key. The site is funded by display ads that appear around the tool but not inside the calculation flow.
Are my inputs saved?
No. Inputs stay in your browser tab. Closing the tab discards them. The site uses Google Analytics for traffic measurement (anonymized) but does not see what you type into the form.
Can I use the CAC Calculator on my phone?
Yes. The tool is responsive and tested on iOS Safari, Android Chrome, and major desktop browsers. Touch targets meet Apple's 44pt and Google's 48dp minimum guidance.
How do I report a bug or suggest improvement to the CAC Calculator?
Email hi@3tej.com with the URL of this page and a description of what you saw vs expected. We typically respond within 72 hours and update calculators when rules or formulas change.
How accurate is the CAC Calculator?
It applies the standard formula. Accuracy is limited only by your input precision. For decisions with material consequences (taxes, medical, legal, structural), use the result as a starting point and verify with a qualified professional in the relevant field.
Is the CAC Calculator free to use?
Yes. 100% free, no signup, no payment, no API key. The site is funded by display ads around the tool but not inside the calculation flow.
Are my inputs saved anywhere?
No. All inputs stay in your browser tab. Closing the tab discards them. The site uses Google Analytics for traffic measurement (anonymized) but the analytics never see what you type into the form.
Does the CAC Calculator work offline?
Yes. Once the page has loaded, it works without internet. The calculation runs in JavaScript on your device.
Can I share results from the CAC Calculator?
Take a screenshot or copy the output. The page doesn't generate shareable URLs for specific calculations - inputs stay in your browser only.
Why are the results different from another cac tool?
Most likely: different formula assumptions, different default values, different rounding rules, or different applicable rates. Check the methodology if both tools document it. Both can be valid for different scenarios.