How to Model Gross Margin for Different Business Models
Gross margin is the first number sophisticated investors check in a financial model, and the benchmark they use depends entirely on your business model. A 60% gross margin is exceptional for a marketplace but mediocre for pure SaaS. Modelling gross margin correctly requires knowing which costs belong in COGS for your specific model, what the benchmark range is for your business type, and whether your margin trajectory improves, holds, or compresses at scale.
Why Gross Margin Modelling Varies by Business Model
Gross margin measures the revenue remaining after the direct costs of delivering your product. Because "direct costs of delivery" means something different for a SaaS company than for a marketplace or a professional services firm, the structure of the COGS model and the resulting gross margin benchmarks differ significantly across business types.
Key benchmarks at a glance:
| Pure SaaS | 70-85% | Hosting, payment processing, support costs |
|---|---|---|
| SaaS with services | 55-75% | Weight of managed services in revenue mix |
| Marketplace (take rate 60-80% | Payment processing, trust and |
SaaS Gross Margin: What to Include
For a pure software-as-a-service business, COGS typically includes: Cloud hosting and infrastructure (AWS, GCP, Azure) scaled with customer count or usage
Third-party API costs consumed per customer (payment processors, mapping services, communication APIs)
Payment processing fees on each transaction
Customer success salaries attributable to direct customer onboarding and support (not account growth)
Amortisation of capitalised software development costs if applicable Product engineering salaries (building features) belong in R&D (OpEx), not COGS, unless they are maintaining the delivery infrastructure. Getting this wrong artificially raises gross margin.
The key modelling question for SaaS is whether hosting and infrastructure costs are variable (per customer or per usage) or largely fixed (flat regardless of customer count). Variable infrastructure costs compress gross margin as volume grows until economies of scale kick in. Fixed infrastructure costs mean gross margin improves significantly as revenue scales.
Marketplace Gross Margin: What to Include
Marketplace COGS depends on whether the business takes transaction risk or simply facilitates transactions.
Pure take-rate model (no fulfilment risk): COGS includes payment processing, fraud and trust and safety operations that scale with transaction volume, and any insurance costs tied to individual transactions. Gross margins in this model are typically high (60-80%) because the primary cost is just friction on the transaction, not delivery of the underlying service.
Marketplace with operations (e.g. staffing, logistics, services): COGS includes the cost of the service being fulfilled, direct operations staff managing the supply side at volume, compliance and verification costs per transaction, and any insurance or indemnity tied to individual placements. Gross margins here are lower (35-60%) because the business is taking on more of the economic risk of the transaction.
For a staffing marketplace like the platform, the key COGS lines were worker pay (the largest single line), employer obligations (NI, holiday pay), compliance and verification operations, and payment processing. The resulting gross margin reflects the spread between the rate charged to employers and the rate paid to workers plus the direct costs of managing that relationship.
Professional Services Gross Margin: The Utilisation Model
Professional services gross margin is primarily driven by two factors: the billing rate per hour and the utilisation rate (percentage of billable hours actually billed).
Gross margin formula for professional services:
Gross Margin = (Revenue - Direct Delivery Costs) / Revenue Direct Delivery Costs = Staff Time Costs + Direct Project Costs Staff Time Costs = (Senior FTE cost × hours) + (Junior FTE cost × hours) The key lever is the ratio of junior to senior staff on deliverables. Higher junior leverage (more junior staff per senior) typically improves gross margin at the cost of quality risk. Higher senior intensity improves quality but compresses margin.
In the model, build utilisation assumptions explicitly. A team of 10 that is 70% utilised on billable work produces very different economics than one that is 90% utilised. And the trajectory --- whether utilisation improves as the team matures and processes stabilise --- drives the gross margin trend in the forecast.
How to Model Gross Margin Trajectory at Scale
For every business model, gross margin should improve as scale increases. The question is by how much and through which mechanism. SaaS: Gross margin improves as fixed infrastructure costs are spread over more customers. Model this explicitly by separating fixed and variable COGS components and showing the fixed cost dilution effect per customer.
Marketplace: Gross margin improves as payment processing rates improve with volume (negotiated rates) and as operations costs per transaction decline through process automation and scale. Show these as explicit assumptions with a rationale.
Professional services: Gross margin improves as utilisation increases and as the junior-to-senior ratio in delivery is optimised. Build utilisation as an explicit driver.
The model should show the gross margin trajectory over the forecast period, with clear attribution of what drives each change. An investor who sees gross margin improving from 45% to 65% over five years without an explanation of the mechanism will ask. Build the explanation into the model before they do.
Common Gross Margin Modelling Mistakes
Flat gross margin across the entire forecast period with no explanation
Engineering costs in COGS for product development work
Customer success costs entirely in Sales and Marketing with nothing in COGS
No separation of fixed vs. variable COGS components
Gross margin that significantly outperforms the business model benchmark with no explanation
Frequently Asked Questions
What gross margin should I target to raise a Series A?
Investors do not have a universal threshold; they benchmark against comparable companies at similar stages and in similar business models. For SaaS, a Series A gross margin below 60% with no clear path to 70%+ will raise questions. For a marketplace with operations, 45-55% at Series A is often acceptable if the trajectory is upward. Know your comparable benchmarks and be able to explain how you compare.
How does gross margin affect valuation?
For SaaS companies, revenue multiples at exit or late-stage fundraising are strongly correlated with gross margin. High-margin SaaS businesses trade at higher multiples because each dollar of revenue converts to more free cash flow. For marketplaces and services businesses, gross margin quality is a signal of operating leverage potential and pricing power.
Should professional services revenue be included in a SaaS company's gross margin?
Yes, but separated. If a SaaS company has both product revenue and professional services revenue, the gross margin for each should be shown separately. Blending them hides the economics of the core product and makes it harder for investors to assess the quality of the recurring revenue stream.
Summary
Gross margin varies by business model and should be modelled with that context in mind. Build COGS using the delivery test, benchmark the output against comparable business models, separate fixed and variable components, show the trajectory and explain the mechanism for improvement, and know the answers to the questions investors will ask about any line that diverges from benchmark. Gross margin is not just a number --- it is the clearest signal of how efficiently your business delivers value relative to what it costs to deliver it.
The Most Common Financial Modeling Mistakes
The most dangerous mistake in startup financial modeling is building a model that only works in one scenario. Real businesses face unexpected churn, slower-than-expected sales cycles, competitive pricing pressure, and hiring delays. A model that only shows the plan without stress testing what happens if ARR growth is 30% lower, or if a key hire takes four months to land is not a planning tool; it is a wishful thinking exercise.
Circular references are a technical trap that undermine model credibility instantly. When an investor opens your spreadsheet and sees #REF errors or formula loops, it signals that the model has not been rigorously tested. Build revenue, cost, and cash flow on separate sheets with clear linking. Every input assumption should live in a dedicated assumptions tab so an investor can change your growth rate and see the full impact cascade through the model instantly.
Overcomplicated models are as problematic as oversimplified ones. A 40-tab model that takes 20 minutes to navigate tells an investor that the builder does not understand what drives their business. The best financial models are opinionated: they make clear which 3-5 assumptions matter most, and they are built to make sensitivity analysis on those assumptions easy.
Financial Modeling Best Practices for Fundraising
The 3-year model is the standard for Series A fundraising; 5 years is standard for later stages. Go beyond 3 years and your assumptions become fiction; stop at 18 months and you signal you have not thought through the full opportunity. Monthly granularity for Year 1, quarterly for Year 2-3 is the conventional structure.
Separate your revenue model from your headcount model and your cost model, and make them link cleanly. Revenue should drive headcount needs (more customers requires more customer success capacity), not the other way around. Build the headcount model with named roles, not just FTE counts investors will ask who these people are.
Document your key assumptions explicitly. The best models include a two-paragraph written explanation of each major assumption: why you chose the number you chose, what the range of outcomes looks like, and what early leading indicators would tell you the assumption is breaking down. This kind of rigorous documentation signals sophisticated financial thinking and dramatically reduces the back-and-forth during due diligence.
How to Improve Your Unit Economics
CAC reduction comes from two sources: more efficient acquisition channels and better conversion. Paid acquisition costs tend to rise as you scale you exhaust the most efficient targeting, CPMs increase, and competition intensifies. The antidote is building organic channels that compound over time: content, SEO, community, and product-led growth. The companies with the best long-term unit economics are the ones where CAC stays flat or falls as they scale, because they have invested in channels that generate demand without linear cost.
LTV improvement requires either increasing revenue per customer (expansion, pricing) or reducing churn (product, success). Expansion is often the more tractable lever customers who have already bought are easier and cheaper to sell to than new prospects. If your net revenue retention is below 100%, fix churn before investing aggressively in new customer acquisition; you are filling a leaking bucket.
Gross margin is the unit economics lever most founders underinvest in improving. Each percentage point of gross margin improvement compounds into meaningfully more cash at scale. Infrastructure cost optimisation, moving from manual service delivery to automated platform delivery, and renegotiating vendor contracts as volumes grow are all levers that improve gross margin without requiring top-line growth.
Get the complete guide with all 16 chapters, exercises, and model templates.
Get Raise Ready - $9.99