Most hiring plans start with a budget. Someone sets a number for people costs, and the org chart grows from there. This feels responsible, but it's the wrong way around. The real question isn’t how much you can spend on people. It’s what revenue you need to hit, and how many people it takes to get there. That’s how a capacity model works. It changes your thinking for every hire.
Teams that use data-driven sales capacity models grow revenue up to 15% faster than those that don’t. The reason is simple. They know exactly how many people they need, when they need them, and what those people should produce. This post shows you how to build that model, what it really costs, and where most teams mess up.
Introducing the capacity model: The "unit of capacity" philosophy
The old headcount playbook starts at the top: Budget first, then see how much you can hire. That turns people into numbers instead of drivers of results. A capacity model flips the script.
Start with your revenue target and work backward. Ask what it takes to generate that number. How many reps? How many CSMs? What support do you need? Each hire becomes a unit of capacity with expected output.
The "revenue power line" is a great way to see this. That’s the minimum headcount you need to keep hitting your growth goals. Drop below it, and growth slows. Hire far above it without enough revenue, and burn grows too quickly. Your job is to stay right on the line, and that means knowing exactly where it sits.
Runway's capacity planning guide says it well: "Capacity planning is about constraints, not wishes. Don’t ask, ‘What do we want?’ Ask, ‘What can we achieve with what we have?’" That discipline turns an idea into a plan.
Building a capacity model for revenue alignment: Tying headcount to top-line goals
The core sales capacity formula is simple:
Sales Capacity = (# of reps) × (individual quota × average quota attainment)
Use it to solve backwards. If your ARR target is $20M and your fully-ramped AEs hit 85% of a $1.2M quota, each produces about $1.02M. That means you need 20 productive AEs by year-end. The trick is, "fully productive" matters here.
New B2B reps take an average of 7 months to ramp up. You can’t count seats alone. Build the productivity curve directly into your model. A typical ramp:
- Month 1: 0% productivity
- Month 2: 25%
- Month 3: 50%
- Month 4: 75%
- From month 5: fully ramped
That’s several months paying full salary before real revenue shows up.
In Runway, you can build this out. The quota attainment workflow uses annual quotas by seniority and market. Add ramp assumptions with dateDiff() to measure months since a rep’s start date. You’ll see per-rep monthly quotas that reflect where each person is on their ramp, rolled up into a bookings capacity model, and matched to your attainment targets.
Sales isn’t everything. Supporting roles need step-function triggers. A typical ratio is one CSM per $2M ARR managed. When ARR hits that mark, it’s time to hire. This keeps your support team in sync with revenue, so you’re never hiring too far ahead or falling behind.
Accounting for the fully burdened reality: Total cost of ownership
Most teams focus on base salary. If that’s all you use, your numbers will be off.
If you budget by base salary alone, you’re underestimating by 30-40%. The full labor rate includes payroll taxes, insurance, retirement contributions, PTO, and overhead. A $60K salary can quickly become $76,900 when you load in the details.
Don’t forget variable comp. Commissions and bonuses scale with performance. If reps nail quota, commission expense goes up. That’s a great sign, but you still need to model it. The same goes for equity. Every hire pulls from your option pool and impacts dilution. Make sure finance tracks this clearly.
Then there’s desk costs. Each new hire triggers a stack of software licenses—Salesforce, Slack, Zoom, your security stack. This can run from $5,000 to $15,000 per employee per year, depending on tools. Hardware can add even more.
In Runway, set up lookup tables by location or department for benefits and payroll tax rates. Connect your HRIS (Rippling, Gusto, BambooHR). The system calculates prorated salary for mid-month starts and exits, applies employer costs, and gives you a monthly cost per employee. Update a benefits rate and every employee in that group updates. No manual rebuilds needed.
Navigating strategic relationships of hiring
Every hire affects your burn rate. That’s obvious. But the timing creates ripple effects, too.
If you delay a hiring class by 30 days, you push out costs by a month. But you also delay the revenue those hires will produce. This can impact your cash more than the saved salaries. Burn rate shapes hiring. Each new team member adds fixed costs and higher burn. Model whether the revenue they bring offsets the extra cash going out and the shorter runway.
Your CAC is connected here, too. Your Customer Acquisition Cost counts every dollar spent to close a deal including fully burdened labor for sales. If you only track base salaries and marketing spend, you’re understating CAC by 30-40%. That matters for channel planning and pricing.
Pipeline coverage is another key. 60% of companies miss revenue targets because they can’t see the full pipeline. Top teams build 3-4× pipeline coverage. If your win rate is 25% and your ARR target is $20M, you need $80M in pipeline. That’s a planning input, not just a sales stat. It drives headcount needs and guides hiring decisions upstream.
One last rule: Don’t outpace your recruiting team. If you plan to hire 20 people in a quarter but your in-house team can close only 8 offers, the rest slip. That slippage needs to show up in the model, not after the fact.
Common pitfalls to avoid
The most common mistake? Assuming growth scales with headcount. It rarely does. Doubling your team won’t double your output. Communication overhead grows even faster. Decisions take longer. Onboarding takes time from your best people. You need to factor in the diminishing returns, especially during rapid scaling.
Don’t use static start dates. Candidates sometimes decline, and start dates shift. If you treat planned hires as guaranteed, your forecast is off from the start. Track hiring lag and build that into your planning. Forecast the real hiring impact, not just when a job opens.
Always model for attrition. No team stays the same forever. Most companies see 10-15% turnover. Replacing a team member can cost 75% to 200% of their salary when you count recruiting, onboarding, and lost productivity. If your model skips this, you’re underestimating risk and total cost.
Automating your hiring model in Runway
Headcount planning is a core workflow in Runway. The platform keeps your capacity model live and connected without heavy spreadsheets.
Start by connecting your HRIS. Runway integrates with Rippling, Gusto, BambooHR, and more. Pull in employee data and build an Employee database that powers headcount and salary models for you.
A recent feature makes this even easier. HRIS integrations bring in details for planned hires as soon as their start month is set. No need to wait. Planned hires show up in your forecasts right away, so you see upcoming costs in full.
Quota and ramp modeling is simple, too. The quota attainment workflow lets you set annual quotas by seniority, add ramp schedules with date logic, and roll it all into a bookings capacity model. Get capacity with ramp and seasonality baked in. Apply attainment, and now you’ve got a bookings forecast that matches the real world. Change a ramp and the model updates instantly.
The headcount efficiency ratio stays wired into the model. If you update the hiring plan, the number updates for you. No manual math.
Scenario planning is easy. Runway's Scenarios feature lets you run different model versions in parallel. Want to see what happens if you delay a hiring class by a quarter? Turn it off and check the impact on burn, runway, and ARR. Want to compare fast hiring against a steady plan? Build both and see them side by side, with variance shown for every driver. Try out a freeze, a new ramp, or a quota change without touching your live plan.
Grow with a revenue-driven approach
A strong capacity model tells you who to hire, when to hire, full costs, and production. It links right to burn, runway, and ARR. Your hiring decisions become strategic, and not just about the budget.
Payroll makes up nearly 70% of budgets for most teams. That’s your biggest lever and your best one. The capacity model lets you pull it with precision, not just with guesses.
Teams that get this right are the ones that beat their revenue targets more often. They build board confidence, make fundraising easier, and avoid expensive hiring risks. They know what each new team member brings to the business.
If you’re ready to leave spreadsheets behind, see how Runway can help you build your model.