DCF Valuation: Complete Guide
A practical, founder-friendly walkthrough of building, debating, and presenting a discounted cash flow model with defensible assumptions.
That was early in my career, and it taught me a hard lesson: DCF is a risk pricing exercise, not a growth story. If you cannot defend the discount rate and the cash conversion, the model collapses.
This DCF valuation guide is how I build models today when a buyer will actually scrutinize them. It is not elegant, but it survives diligence.
What a DCF actually measures
DCF measures how much cash a buyer can take out after funding growth. That is it. A DCF valuation guide that starts with EBITDA and never bridges to free cash flow is not a DCF.
Most advisors will disagree, but I prefer to underwrite cash at a 10-15% discount rate and be surprised on the upside. Optimistic models get shredded in committee.
This mindset saved a TechFlow-style services business I advised. We cut the growth assumption from 22% to 12%, and the buyer still paid 4.0x because the cash conversion was provable.
Step-by-step DCF build that buyers accept
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Step 1: normalize earnings
Remove unsupported add-backs and reconcile EBITDA to audited statements.
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Step 2: convert to free cash flow
Subtract taxes, capex, and working capital movements. If cash conversion is weak, explain why.
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Step 3: set the forecast
Use conservative revenue growth and margin assumptions tied to capacity and pricing power.
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Step 4: pick a defensible WACC
Base WACC on real risk factors, not wishful industry averages.
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Step 5: build terminal value
Use a modest terminal growth rate and check it against a sane exit multiple.
WACC is where most models break
If your customer concentration is above 25% or your gross margin is volatile, a low WACC is not credible. Buyers will adjust it.
Terminal value traps to avoid
Terminal value can be 60-70% of a DCF. That is why buyers attack it first. If you assume 4% perpetual growth in a mature market, they will cut it. If your exit multiple is higher than current comps, they will cut it.
The honest approach is to triangulate. Use a modest perpetual growth rate, then sanity-check with a market multiple range. If the two diverge, your assumptions are too aggressive.
A DCF valuation guide that survives diligence treats terminal value as a range, not a single number. Project your numbers with our free cash flow calculator and IRR calculator. For how DCF compares to other valuation methods, see our complete valuation methods guide.
How buyers stress-test your DCF
Growth haircut
-5 to -8 points
If your base case assumes 18%, they will test 10-13%.
Margin compression
-3 to -5 points
Input costs and pricing pressure hit forecasts first.
WACC uplift
+200-400 bps
A small discount rate change can erase the premium fast.
Key Takeaways
Conclusion
A DCF valuation guide is only useful if a buyer can defend it after you leave the room. If the model relies on heroic growth or a soft discount rate, it will be rewritten.
If you want a defensible baseline, build your DCF with Valuefy and test the discount rate and terminal value against a conservative scenario. That is how you protect the price before diligence starts.
Frequently Asked Questions
How long should a DCF forecast be?
I use five years for most SMEs. Longer forecasts add false precision unless you have long-term contracts that lock in revenue.
What is a reasonable terminal growth rate?
For most mature businesses, 2-3% is defensible. Anything higher needs strong evidence and market support.
Do buyers always trust a DCF?
They trust the logic, but they will still cross-check with multiples. If the range does not reconcile, they will reprice it.
Related Guides in This Series
Business Valuation Methods: Complete Guide
A founder-friendly overview of income, market, and asset-based valuation approaches with guidance on when to blend methods.
Adjusted EBITDA: Complete Calculation Guide
Learn how to calculate Adjusted EBITDA, document add-backs, and use the metric to benchmark valuation multiples with confidence.