I've sat in on pitch meetings where founders presented 30-slide decks packed with metrics. LTV:CAC ratios, NPS scores, DAU/MAU ratios, cohort retention curves, payback period by channel. Very impressive. Also completely irrelevant at $15K MRR.
Here's a controversial opinion: early-stage startups (pre-Series A, under $1M ARR) should track exactly five metrics. Everything else is noise that makes you feel productive while distracting you from the numbers that actually determine whether your business survives.
These are the five. I'll explain what each one tells you, how to calculate it, and at what point you should start worrying.
1. Monthly Recurring Revenue (MRR)
MRR is the total predictable revenue your business generates each month. If you have 200 customers paying $50/month and 30 customers paying $200/month, your MRR is $16,000.
Why it matters: MRR is the heartbeat of a subscription business. Not annualized revenue, not “bookings,” not pipeline — actual recurring revenue that hits your bank account every month. It's the single most honest number in your business.
What to track: Month-over-month growth rate. At the early stage, you want to see 15–20% MoM growth. That sounds aggressive, but remember — 15% growth on $10K MRR is only $1,500 in new revenue. If you can't add $1,500/month to a business with product-market fit, you might not have product-market fit.
The warning sign: Two consecutive months of flat or declining MRR growth rate. Not flat MRR — flat growth rate. Going from 18% to 12% to 8% growth is a deceleration pattern that needs investigation immediately.
2. Burn Rate
Burn rate is how much cash you spend each month beyond what you earn. If your monthly expenses are $65K and your MRR is $16K, your net burn is $49K/month.
Why it matters: Revenue gets the glory. Burn rate determines survival. I've watched founders celebrate hitting $50K MRR while burning $120K/month. That's not a business — that's a countdown timer.
What to track: Gross burn (total monthly spend) and net burn (spend minus revenue). More importantly, track the trend. Is your net burn increasing, decreasing, or flat? If your MRR is growing 15% monthly but your burn is growing 10% monthly, the lines will eventually cross. But “eventually” matters — is it 6 months or 24 months? Use a burn rate calculator to model it.
The warning sign: Net burn increasing faster than MRR for three consecutive months. That means each new dollar of revenue is costing more than the last, which is the opposite of how a scalable business works.
3. Runway
Runway is how many months you can operate before you run out of cash. Cash in the bank divided by monthly net burn. $490K in the bank at $49K/month net burn = 10 months of runway.
Why it matters: Runway is the single most important number for a pre-revenue or early-revenue startup. It determines every decision: can you hire? Can you spend on marketing? Can you afford to pivot? Can you wait three months for a big deal to close?
What to track: The number itself, updated weekly. Not monthly — weekly. At the early stage, one bad month can shave 20% off your runway. You need to see that in real time.
The warning sign: Anything below 6 months demands action. Below 6 months, you should either be actively fundraising, aggressively cutting costs, or both. Below 3 months, you're in emergency mode. The founders who get caught at 3 months of runway are almost always the ones who weren't checking weekly.
4. Customer Acquisition Cost (CAC)
CAC is how much you spend to acquire one new customer. Total sales and marketing spend divided by new customers acquired in the same period. If you spent $12K on marketing last month and acquired 40 customers, your CAC is $300.
Why it matters: CAC tells you whether your growth is sustainable. You can grow MRR by throwing money at ads, but if each customer costs $300 to acquire and pays $50/month, you need 6 months just to break even on the acquisition cost. That math only works if retention is high.
What to track: CAC by channel. Your blended CAC might look fine ($300), but when you break it down, organic search customers cost $40 (great) and paid social customers cost $580 (not great). The blended number hides the problem.
The warning sign: CAC increasing quarter over quarter. As you exhaust your initial audience (the early adopters who were easiest to reach), CAC naturally rises. If it rises faster than your average revenue per customer, you have a unit economics problem that will get worse with scale.
5. Gross Margin
Gross margin is revenue minus the direct cost of delivering your product, expressed as a percentage. If your MRR is $16K and it costs $3,200/month in hosting, support staff, and payment processing to deliver the service, your gross margin is 80%.
Why it matters: Gross margin determines how much of every revenue dollar you get to keep. A SaaS business with 80% gross margin has $0.80 of every dollar available to cover operating expenses and generate profit. A services business with 40% gross margin has $0.40. That difference compounds enormously at scale.
What to track: The percentage, and whether it holds as you grow. Early-stage SaaS should target 70–85%. Below 60%, investors will question whether it's really a software business or a services business in disguise. Marketplaces and e-commerce run lower (30–50%) but have different economics.
The warning sign: Gross margin declining as revenue grows. This usually means your infrastructure costs or support costs are scaling linearly with customers when they should be scaling sub-linearly. It's a sign that your product has scaling problems that will get expensive fast.
What About Everything Else?
NPS, DAU/MAU, cohort retention, LTV:CAC ratio, payback period, magic number, Rule of 40 — these are all real metrics that matter at the right stage. But at pre-Series A, tracking them is often a form of procrastination. You're building dashboards instead of building product and talking to customers.
Get these five numbers right first. When your MRR hits $100K and you're preparing for a Series A, then add the sophisticated metrics. Until then, five numbers on a single dashboard, updated weekly, is all you need to make every decision that matters.
