Your waterfall is one mis-dragged formula away from a wrong number in a board deck. Spreadsheets are flexible, universal, and effectively free, which is exactly why almost every exit model starts in one. For a first pass, that is the right call. But the moment the model has to be correct, reproducible, and defensible in front of a board, an investor, or a diligence team, the spreadsheet stops being a convenience and becomes the risk.
That is the real question behind cap table software vs Excel: not "which is more powerful," but "which one returns the right number, the same way, every time." This page is a fair comparison: where Excel genuinely wins, where it silently fails, a worked example you can check yourself, and a free starter template to get you going.
Waterfalls vs Excel at a glance
Excel is a general-purpose canvas; Waterfalls is a purpose-built exit-modeling engine. The table below keeps it terse and fair; the rest of the page is the why.
| Capability | Excel / spreadsheets | Waterfalls |
|---|---|---|
| Cost | Free / already owned | Free plan; Pro $39/mo; Enterprise custom; no credit card |
| Flexibility | Total: model any layout or one-off structure | Structured cap-table + exit modeling (purpose-built, not freeform) |
| Ubiquity / access | Everyone has it; any advisor can open the file | Web app; no install; account required |
| Math correctness | As correct as the last formula you typed | Decimal-precision engine, externally validated across 30 exit values, 303 automated tests |
| Hard terms (participation caps, pari-passu, greater-of, convertibles, carve-outs) | Hand-built conditional logic; easy to get subtly wrong | Modeled explicitly by the engine |
| Audit trail | No structured breakdown: tracing the logic means inspecting nested formulas by hand | Step-by-step, tier-by-tier breakdown + invariant checks on every run |
| Reproducibility | Version forks; the “final_v7” problem | One model; same correct answer every time |
| Sensitivity analysis | Manual, per scenario | Each exit value modeled on screen; side-by-side sensitivity coming soon |
| Sharing | Email a file; recipient can edit or break it | Secure share links, optional password, interactive view (Pro and Enterprise) |
| Best for | Rough first pass, bespoke one-offs, total control | Correct, defensible, repeatable exit/waterfall models |
Where Excel and spreadsheets genuinely win
This is not a strawman. Excel earned its place at the center of finance for good reasons, and any honest comparison has to start there:
The honest takeaway: for a first-pass estimate, or a one-off structure no tool models, a spreadsheet is the right tool. The case for switching is not "Excel is bad"; it is "the number now has to be right, and stay right."
Where spreadsheets break, and where Waterfalls wins
Everything above holds until the model has to be correct under scrutiny. That is where a hand-built sheet starts working against you, and where a validated engine earns its keep.
Formula and drag-fill errors
The classic failure mode is silent: a copied or dragged formula references the wrong
cell, a hardcoded number quietly overrides a formula, or a row gets inserted and a
SUM range fails to follow. Nothing turns red. The sheet still returns
a number, just the wrong one. Waterfalls answers this with a
validated engine (externally checked against an independent
finance-firm model across 30 exit values, and backed by 303 automated tests) running
decimal-precision math with no floating-point drift, so the same
inputs return the same correct answer every time. (More on
how a waterfall is calculated.)
The terms that break most spreadsheets
Participation caps, stacked seniority versus pari-passu, the greater-of preference-vs-as-converted decision, SAFE and note conversion with real interest accrual, underwater options, and carve-outs all demand conditional logic that hand-built sheets get subtly wrong. Each clause looks fine in isolation; the interactions are where the number drifts. Waterfalls models them explicitly, including liquidation preferences and participating preferred with caps, so the logic is applied in the right order, not reconstructed by hand on each new deal.
No audit trail
A spreadsheet shows you the result, not the reasoning. When the board asks "why does Series B receive that," you are tracing nested formulas live, in front of the room. Waterfalls produces a step-by-step, tier-by-tier breakdown of how every dollar flows through the distribution waterfall, and runs invariant checks on every calculation: total distributed equals the exit value, no negative payouts, nothing left unaccounted for.
Version chaos and reproducibility
model_final_v7_REALLY_final.xlsx, three forks in three inboxes, and no
single source of truth. Waterfalls keeps one model, shareable via a secure link
(Pro and Enterprise) with an interactive mode viewers can flex
without ever touching your saved version.
A worked example: one wrong formula, two very different board decks
Numbers make this concrete. Here is one clean scenario, the error a spreadsheet quietly makes, and the result a validated engine returns, arithmetic you can check.
The spreadsheet way (and the error)
The model-builder writes the participation as "preference plus pro-rata of the remainder," but a dragged formula applies that 40% to the full $30,000,000.00 exit instead of the remainder after the preference, and the 3x cap never gets wired in. The result:
Step (as the sheet computes it)
The validated way
Waterfalls applies the preference first, then participation only on the remainder, enforces the 3x cap as a ceiling on the stake, and takes the greater-of participating versus simply converting to common for 40%:
Tier
The sheet returns a confident, wrong number for Series A, and nobody catches it, because it still "adds up" to $30,000,000.00 visually. The verifier confirms the total distributed equals the $30,000,000.00 exit value with no negative payouts. The spreadsheet overstated Series A by $4,000,000.00, money it silently took straight out of the common column.
Who should pick which
Pick Excel or a spreadsheet when:
- You need total layout flexibility or a one-off, bespoke structure no tool models.
- You want a rough, first-pass estimate and nothing more.
- You genuinely can't add another tool to the stack right now.
Pick Waterfalls when:
- The number has to be correct and defensible: board, LPs, diligence.
- You model the same exit repeatedly across a range of exit values.
- You're handling participation caps, stacked preferences, convertibles, or carve-outs.
- You need to share a scenario without emailing a file (Pro and Enterprise).
Honestly, many teams use both: sketch in a sheet, then model the real waterfall in Waterfalls to check it. The spreadsheet is where you think; the engine is where you're sure. If you're still building the cap table itself, start with cap table modeling structure and calculations.
Want a free waterfall model Excel template?
A clean, well-built starter sheet is a legitimate way into this: a cap-table layout plus a worked single-exit waterfall tab (preference → participation → pro-rata). It's a solid starting point, and an honest demonstration of where a static sheet stops: the participation cap and the greater-of decision are exactly the places you saw a hand-built sheet drift above.
Free template, coming soon. We're putting the finishing touches on a downloadable starter template. In the meantime, the fastest way to model a waterfall that's correct from the first cell is to skip the spreadsheet entirely and build it in Waterfalls free (no card, your data always kept).
If charting the result is what you're after rather than modeling it, see how to build a waterfall chart in Excel. A chart visualizes a number you already trust; this page is about getting that number right.
Frequently asked questions
Can you model an exit waterfall in Excel?
Yes, and most people start there. Excel handles simple waterfalls fine. It struggles once participation caps, stacked seniority, the greater-of preference-vs-as-converted decision, or convertible interest enter the model, where hand-built formulas are easy to get subtly and silently wrong.
Why use a tool instead of a cap table spreadsheet?
For correctness and reproducibility. A spreadsheet is only as right as the last formula you typed, and a dragged or hardcoded cell can return a wrong number with no warning. Waterfalls uses a validated, decimal-precision engine, externally checked across 30 exit values and backed by 303 automated tests.
Is Waterfalls free?
There's a free plan with no credit card that includes the full modeling engine and 2 saved waterfalls. Pro is $39/mo with unlimited waterfalls, shareable links, and priority support; Enterprise is custom. You can cancel anytime, and your projects are always kept.
Can I see how Waterfalls reached a number?
Yes. Every calculation includes a step-by-step, tier-by-tier breakdown showing how proceeds flow through preferences, participation, conversion, and carve-outs, plus invariant checks confirming the total distributed equals the exit value with no negative payouts. A spreadsheet shows the result, not the reasoning.
Can I share a Waterfalls model with my board or investors?
Yes, on Pro and Enterprise. You can share a scenario via a secure link with optional password protection, including an interactive mode viewers can flex without altering your saved model, instead of emailing a spreadsheet anyone can edit or break.
