Projecting Capex and Reinvestment
Operating profit is not cash. The gap between the two is capital expenditure (CapEx), the money a company spends to build, buy, and maintain the assets that generate future earnings. A company might report 30% operating margins but require CapEx of 8% of revenue just to sustain growth. The difference—22% of revenue—is available for debt service, dividends, buybacks, and shareholders. That 22% is what matters in a DCF.
Yet CapEx is where many models go wrong. Beginners either ignore it (treating operating profit as if it were cash), or they project it too simply (assuming a constant percentage of revenue forever). CapEx is neither constant nor negligible. It varies by industry, by growth rate, and by stage of the company's life cycle. This article teaches you to forecast CapEx with precision.
Quick definition: CapEx is capital expenditure—the cash spent to purchase, construct, or improve fixed assets (property, plants, equipment, software, vehicles, etc.). In a DCF, you forecast CapEx as a percentage of revenue or in absolute dollars, then subtract it from operating profit to arrive at free cash flow. The key insight: CapEx is a reinvestment; if you do not reinvest, future operating profit declines.
Key Takeaways
- CapEx varies dramatically by industry: asset-heavy industries (utilities, railroads, oil & gas) spend 10–20%+ of revenue; asset-light industries (software, consulting) spend 1–3%.
- Maintenance CapEx (the minimum needed to sustain current earnings) is separate from growth CapEx (the spending needed to support incremental revenue). Growth CapEx is the critical DCF input.
- CapEx intensity (CapEx as % of revenue) declines as companies mature. A hypergrowth software company burning 5% CapEx at $1B revenue might run at 2% at $5B revenue.
- Ignore depreciation as a guide to CapEx. Many companies depreciate assets over 10 years but replace them every 7. Use historical CapEx, not D&A, to project forward.
- CapEx is lumpy. Assume an average annual CapEx, not a smooth line. Some years will be above average (building a new facility), some below (underinvestment).
- Asset-light business models (SaaS, marketplaces, advertising) allow for high free cash flow conversion. Asset-heavy models (manufacturing, transport) do not.
Starting Point: Historical CapEx and Intensity
Pull 5–10 years of CapEx from the cash flow statement and calculate CapEx as a percentage of revenue.
A typical analysis for an industrial equipment manufacturer:
| Year | Revenue ($M) | CapEx ($M) | CapEx % | Notes |
|---|---|---|---|---|
| 2019 | $3,000 | $240 | 8.0% | Normal year |
| 2020 | $2,500 | $200 | 8.0% | Recession, but capex held |
| 2021 | $3,200 | $380 | 11.9% | Major facility expansion |
| 2022 | $3,500 | $280 | 8.0% | Expansion complete, normalized |
| 2023 | $3,800 | $304 | 8.0% | Steady-state CapEx |
| 2024 | $4,100 | $328 | 8.0% | Consistent level |
The company's normalized CapEx is 8% of revenue. 2021 was an outlier (facility expansion). For forecasting, use 8% as the base, but be ready to add discretionary CapEx for known initiatives (new plants, major equipment refreshes, IT upgrades).
Next, break down historical CapEx by type:
| Category | 2024 ($M) | % of Total | Purpose |
|---|---|---|---|
| Maintenance CapEx | $180 | 55% | Equipment replacement, facility maintenance |
| Growth CapEx | $100 | 30% | New production lines, facility expansion |
| IT and Systems | $35 | 11% | Software, data infrastructure |
| Real Estate | $13 | 4% | Offices, warehouses |
| Total | $328 | 100% |
This breakdown is illuminating:
- Maintenance CapEx ($180M) is roughly tied to depreciation ($150M reported on income statement). If D&A is $150M and maintenance CapEx is $180M, the company is replacing assets slightly faster than accounting depreciation (typical for companies managing asset longevity).
- Growth CapEx ($100M) is the discretionary spend tied to growth plans. Project this based on revenue growth assumptions: if you forecast 5% revenue growth, you might assume growth CapEx of $95M (slightly below historical, reflecting maturing growth). If you forecast 10% growth, you might assume $150M.
CapEx Drivers: Asset-Heavy vs. Asset-Light
Industry fundamentals dictate CapEx intensity.
Asset-Heavy Industries:
- Utilities: 12–15% of revenue (power plants, grids, distribution, vehicles).
- Railroads: 8–12% of revenue (locomotives, track, switching infrastructure).
- Oil & Gas: 15–25% of revenue (drilling, pipelines, refineries, platform maintenance).
- Integrated Semiconductors: 8–15% of revenue (fabrication plants are capital-intensive).
- Retail (stores): 3–5% of revenue (store build-outs, remodels, equipment).
Asset-Light Industries:
- Software (SaaS): 1–3% of revenue (data centers, office space).
- Consulting: 0.5–1% of revenue (offices, tools).
- Advertising (digital): 1–2% of revenue (data centers, systems).
- Marketplace / E-commerce Platform: 2–4% of revenue (minimal inventory, some infrastructure).
A key insight: higher CapEx intensity reduces free cash flow, which reduces enterprise value, all else equal. A software company with 30% operating margin and 2% CapEx intensity can convert 28%+ of revenue to free cash flow. An oil & gas company with 25% operating margin and 20% CapEx intensity can convert only 5%+ to free cash flow. The software company is more valuable per dollar of operating profit.
This is why "asset-light" business models command premium valuations. They convert earnings to cash more efficiently.
Maintenance CapEx vs. Growth CapEx
The most useful decomposition is maintenance vs. growth.
Maintenance CapEx is the spending required to keep the business running at current capacity. If a company does zero maintenance CapEx, its asset base decays, and operating profit eventually declines. Maintenance CapEx is roughly equal to depreciation (though it can exceed or fall short depending on asset replacement cycles and inflation).
Growth CapEx is the incremental spending tied to revenue expansion. If you forecast 5% revenue growth, growth CapEx is the capital required to support that 5%.
The relationship:
Free Cash Flow = Operating Profit − Maintenance CapEx − Growth CapEx − Change in Working Capital − Taxes
If maintenance CapEx alone consumes 50% of operating profit, there is very little room for growth CapEx or shareholder distributions. This is the dynamic in mature, capital-intensive industries: they require constant feeding just to stay even.
To project, estimate:
-
Maintenance CapEx = Depreciation (conservative), or use the ratio of historical maintenance CapEx to historical depreciation (e.g., 1.2x D&A).
-
Growth CapEx = Incremental revenue growth × historical growth CapEx per dollar of growth.
Example:
| Metric | 2024A | 2025E | 2026E | 2027E |
|---|---|---|---|---|
| Revenue | $4,100M | $4,600M | $5,060M | $5,566M |
| Growth % | — | 12% | 10% | 10% |
| Maintenance CapEx (assume D&A) | — | $160M | $170M | $190M |
| Growth CapEx (assume $0.15 per new dollar revenue) | — | $75M | $69M | $76M |
| Total CapEx | — | $235M | $239M | $266M |
| CapEx % | — | 5.1% | 4.7% | 4.8% |
Note: CapEx as a percentage declines as revenue base grows. Absolute CapEx can stay flat or rise, but relative to revenue, it declines. This is normal for mature companies.
CapEx and Growth: The Relationship
A critical question: how much CapEx is required per dollar of growth?
For a manufacturing company, each new production line costs $50M and generates $100M in incremental revenue annually. CapEx intensity on growth is $0.50 per dollar of new revenue.
For a software company, each new cloud instance costs $1M and serves $20M in new ARR. CapEx intensity on growth is $0.05 per dollar of new revenue.
This ratio—call it the growth CapEx ratio—drives the sustainability of growth. High-growth companies with low growth CapEx ratios can reinvest a small portion of incremental profit back into growth and distribute the rest to shareholders. High-growth companies with high growth CapEx ratios consume all incremental profit (or more) in CapEx, leaving nothing for shareholders until growth slows.
A high-growth cloud software company with 40% operating margins and $0.05 growth CapEx ratio can grow at 30% and still generate 35% free cash flow margins. A high-growth biopharmaceutical company with 40% operating margins and $0.40 growth CapEx ratio (R&D as CapEx) grows at 20% but FCF margins are only 10%.
Lumpy and Discretionary CapEx
Real CapEx is not smooth. A company builds a new factory once every 5 years, not a little each year.
When projecting, ask:
- Are there scheduled CapEx projects (new facility, major IT system, new product line)?
- When will they occur?
- What is the cost?
- What is the benefit (incremental revenue or margin)?
Example: A retail company plans a major store remodel program.
- Years 1–3: Remodel 100 stores per year at $2M per store = $200M/year ($5M revenue per remodeled store).
- Year 4: Remodel 50 stores = $100M (winding down).
- Year 5+: Normalized CapEx = $150M (new stores + maintenance).
This is visible in the company's guidance, press releases, and 10-K disclosures. Do not guess; use what management has announced.
CapEx by Business Segment
Large diversified companies often have different CapEx intensities by segment. Break it down:
| Segment | Revenue | CapEx | CapEx % | Drivers |
|---|---|---|---|---|
| Manufacturing | $2,000M | $200M | 10% | Plant capacity, equipment replacement |
| Services | $1,500M | $60M | 4% | Field support vehicles, equipment |
| Software | $800M | $30M | 3.8% | Data centers, systems |
| Total | $4,300M | $290M | 6.7% |
When you forecast, the segment breakdown allows you to adjust CapEx intensity for each segment independently. If you assume manufacturing revenue grows 2% but services grows 8%, blended CapEx intensity changes.
Sensitivity to CapEx Assumptions
CapEx is highly sensitive in DCFs. A 1% change in CapEx intensity (as a percentage of revenue) changes free cash flow by roughly 1% of revenue, which cascades into 5–10% changes in enterprise value (depending on discount rate and growth rate).
Build a sensitivity table:
| CapEx Intensity | Terminal FCF ($M) | Enterprise Value ($M) | Implied Multiple |
|---|---|---|---|
| 3% | $800 | $8,500 | 10.6x |
| 4% (base) | $750 | $8,000 | 10.0x |
| 5% | $700 | $7,500 | 9.4x |
| 6% | $650 | $7,000 | 8.8x |
Small changes in CapEx intensity create material differences in value. This is why precision matters.
Common CapEx Projection Mistakes
1. Using depreciation as a proxy for CapEx. Depreciation is an accounting allocation. CapEx is cash. A company might depreciate assets over 10 years but replace them every 7, creating a mismatch. Use historical CapEx, not D&A, as your guide.
2. Ignoring lumpiness. You assume 5% CapEx every year. In reality, the company builds a new facility in year 3 (spike) and does minimal CapEx in years 4–5 (valley). Smooth the average, but acknowledge the lumpiness in scenario analysis.
3. Assuming CapEx scales linearly with revenue. CapEx intensity typically declines as companies mature. A 40-person SaaS startup might spend 5% on CapEx. At $500M ARR, CapEx is 2%. Assume deceleration in later years.
4. Missing the distinction between growth CapEx and maintenance CapEx. You project 10% revenue growth and assume CapEx is 5% of revenue (for growth) when actually you should assume maintenance CapEx (say, 2% of revenue) plus growth CapEx ($0.10 per dollar of new revenue). The miss is small on revenue but material on FCF.
5. Assuming away needed CapEx. You assume a company can grow 20% with flat absolute CapEx. That works for one year; by year 3, underinvestment shows up as asset deterioration, quality problems, or customer service failures. If growth is real, CapEx must support it.
6. Ignoring CapEx efficiency over time. Technology companies spend heavily on infrastructure in early growth years, then leverage that base. CapEx per revenue dollar declines not because the company cuts corners, but because the installed base amortizes improvements. Model this productivity improvement, especially for software and cloud companies.
Real-World Examples
Example 1: Amazon (2010–2024)
Amazon's CapEx intensity evolved dramatically:
- 2010–2012: 2–3% of revenue (early cloud, minimal capex).
- 2013–2017: 4–6% of revenue (major buildout of AWS infrastructure and fulfillment centers).
- 2018–2020: 4–5% of revenue (scaling fulfillment and cloud, but leverage sets in).
- 2021–2024: 7–9% of revenue (AI infrastructure, grocery stores, and accelerated fulfillment expansion).
A DCF in 2010 assuming Amazon would stay at 3% CapEx intensity would have massively overstated FCF. But a DCF in 2015 assuming Amazon would stay at 6% indefinitely would have missed the operating leverage that eventually brought it back down to 5%. CapEx intensity is not static; it reflects growth phase and strategic investments.
Example 2: Utility Stocks (Duke Energy, NextEra)
Utilities are capital-intensive by nature: CapEx runs 12–15% of revenue to maintain and upgrade grids. This is forecast with high predictability because it is regulatory and essential.
A DCF for a utility assumes CapEx at 12–13% of revenue forever (or until the network is fully modernized, then it might drop to 10%). The low free cash flow margin (8–10% even with 20%+ operating margins) reflects the capital intensity. Utilities are valued on dividend yield, not FCF yield, because their ability to return cash to shareholders is constrained by CapEx needs.
Example 3: Tesla (2015–2024)
Tesla's CapEx intensity spiked during factory buildouts:
- 2015–2017: 2–3% of revenue (Gigafactory 1 under construction but not yet capitalized as CapEx).
- 2018–2020: 4–6% of revenue (heavy investment in production capacity).
- 2021–2024: 3–4% of revenue (factories operational, lower incremental CapEx per unit as leverage sets in).
A DCF in 2018 assuming Tesla would need 5% CapEx per vehicle long-term was conservative (factories were ramping). A DCF in 2023 assuming that same 5% rate was optimistic (Tesla had built capacity and could grow at lower CapEx intensity).
Frequently Asked Questions
Q: Should I forecast CapEx to decline as a percentage of revenue as the company matures?
A: Yes, typically. As companies scale, CapEx intensity often declines because fixed infrastructure investments (data centers, facilities) are spread over larger revenue bases. However, if a company is in a growing industry with technological obsolescence (semiconductors, cloud), CapEx intensity might stay elevated. Base your assumption on the company's history and industry norms.
Q: How do I account for M&A spending in my CapEx forecast?
A: Acquisitions are not CapEx for DCF purposes; they are returns to sellers, reflected in enterprise value or balance sheet changes. In your explicit forecast, ignore M&A CapEx. If you are modeling M&A as a growth driver, add it as a separate line item, separate from organic CapEx.
Q: Is CapEx tax-deductible in my DCF calculation?
A: No. CapEx is a cash outflow but not a deduction from operating profit (which is already calculated after depreciation). Depreciation is the tax deduction; CapEx is the cash spend. Your free cash flow calculation subtracts CapEx after calculating taxes on operating profit.
Q: What if the company has been underinvesting in CapEx (relative to depreciation)?
A: If CapEx is consistently less than D&A (say, CapEx is 60% of D&A), the company is drawing down its asset base. This is unsustainable; eventually, equipment fails, quality suffers, or production capacity shrinks. Assume the company will normalize spending to match (or exceed) depreciation. This is especially critical for asset-heavy businesses.
Q: Should I assume CapEx continues into the terminal value period?
A: Yes. In the terminal value, assume CapEx equals depreciation (steady-state replacement) plus growth CapEx to support perpetual growth. If terminal growth is 2% and growth CapEx ratio is $0.10 per dollar of new revenue, and terminal operating profit is $1,000M, terminal CapEx is roughly D&A (equivalent to depreciation) plus 2% × $1,000M × $0.10 = $20M. This ensures the terminal value reflects the reinvestment needed to sustain perpetual growth.
Q: How do I model environmental compliance CapEx (e.g., pollution control, emissions reduction)?
A: Treat it as maintenance CapEx in asset-heavy industries (utilities, oil & gas, chemicals). It is not discretionary; it is required by regulation. Forecast it as an increment to normalized maintenance CapEx, especially if regulations are tightening. The company will spend it or be fined, so include it.
Related Concepts
- Return on invested capital (ROIC): CapEx is invested capital. High ROIC companies generate strong returns on their CapEx; low ROIC companies waste it. CapEx intensity is a component of the calculation.
- Cash conversion cycle: CapEx is a source of working capital. A company building a new factory (CapEx) may also increase inventory and receivables (working capital). Both consume cash.
- Free cash flow: CapEx is the first deduction from operating profit to arrive at FCF. Errors in CapEx assumptions cascade into FCF errors.
- Terminal value sustainability: Terminal value assumes the company reinvests CapEx perpetually. If terminal CapEx is insufficient, the terminal value is unsustainable.
Summary
CapEx is the bridge from operating profit to free cash flow. Rigorous projection requires understanding the industry's capital intensity, breaking down maintenance vs. growth CapEx, and modeling how CapEx intensity changes as the company matures and as growth rates decelerate. Asset-light companies can convert a high percentage of operating profit to free cash flow; asset-heavy companies cannot. This difference is fundamental to valuation.
A DCF that ignores CapEx or assumes a naive constant rate is not just imprecise—it is dangerous. Small errors in CapEx assumptions create large errors in free cash flow, which cascade into valuation errors that can be multiples of the error itself.
Next
Projecting working capital changes — How to model the cash consumed by (or released by) increases and decreases in receivables, inventory, and payables—often overlooked but sometimes material to free cash flow.