Sales & PartnershipsFree tool
Sales ROI Calculator and Business Case
A one-page business case and three-year ROI model built from the buyer's own numbers, with every figure sourced and only cash benefits in the payback.
Free to start · Opens in your River workspace, ready to edit and share
How to build a B2B business case and ROI model
A business case for a B2B purchase is the document your buyer's champion uses to get the spend approved. It compares two futures: buying, and carrying on as they are. The ROI model puts numbers on the gap: what it costs, the cash it returns, the month it pays back and its net present value. A good one uses the buyer's own figures, names the source of every number, and survives a line-by-line check by finance.
Build it to be checked, not to impress. A modest return with a source on every line is easier to defend than a big number nobody can trace.
Start from the buyer's own numbers
Finance will ask where each number came from, so record the answer beside it. Every input comes from one of four places.
Where each input comes from
| Source | What to record | Example |
|---|---|---|
| The buyer said it | Their words, who said them and when | "About $9,000 a month on temps at quarter end." Operations director, May 12 |
| Their document | The document's name and page | Aging report, page 2: $12,000 in late fees last year |
| You measured it | How and when you measured it | Timed 20 invoices: 6 minutes each |
| Your assumption | Labeled as yours, in the model itself | Half the time saved comes back in year one |
Discovery is where these numbers get said out loud: volumes, time per task, error rates, what workarounds cost. A discovery call questions template helps you ask for them. If the call was recorded, quote the transcript, not your notes.
An industry average is not their number
A benchmark from a vendor report describes someone else's business. If you lack a figure, label your assumption as yours and show the case without it.
Cost what happens if they don't buy
Your benefit is the gap between two futures, not the size of today's problem. The UK Treasury's Green Book, the government's guidance on appraising spending, calls the future without the purchase business as usual1: "the outcome that is expected if current arrangements continue."
That future isn't frozen. The Green Book says business as usual "does not mean doing nothing": people keep working on their problems without you. If late fees are already falling after a policy change, that fall is what the Green Book calls "deadweight." Count only the drop beyond it.
Carrying on has costs too: temps, overtime, a planned hire, an old system up for renewal. Cost each one; they are often your champion's strongest argument.
Count every cost, including theirs
The buyer pays more than your invoice. Add implementation fees, their project hours, training time and any months of running old and new systems side by side. Leave these out and finance will add them back.
Price their time at a loaded rate: salary plus benefits, divided by hours worked. For full-time private industry workers in June 2026, benefits cost employers $17.03 an hour on top of $36.97 in wages2, the Bureau of Labor Statistics reports. A full-time loaded rate is about 1.46 times the wage.
Plan for overruns. In a 2011 Harvard Business Review article, Bent Flyvbjerg and Alexander Budzier analyzed 1,471 IT projects. The average cost overrun was 27%, and one project in six overran by 200% on average3. Check what a 50% setup overrun would do to payback.
Separate cash from non-cash benefits
In the Green Book's terms, a cash-releasing benefit1 affects a public body's income or spending, and a non-cash-releasing benefit doesn't. Apply the same test to your buyer's budget.
Hours saved usually fall on the non-cash side. If 40 people each save 3 hours a week and all 40 stay on payroll, no cost has gone down. An hour becomes cash only when a named cost stops (contractor fees, overtime, a planned hire) or the time moves onto work that earns revenue.
Give every benefit an owner: the team whose budget changes. Forrester's 2026 State of Business Buying report found the typical buying decision includes 13 internal stakeholders4. When a saving lands outside your champion's budget, a stakeholder and champion map shows who else needs to be in the room.
A benefit register (illustrative)
| Benefit | Per year | Source | Cash? | Owner |
|---|---|---|---|---|
| Quarter-end temps | $36,000 | Buyer said it, May 12 | Cash: agency bills stop | Finance operations |
| Planned hire dropped | $74,000 | Their hiring plan | Cash: salary and benefits not paid | Accounts payable |
| Late fees beyond the trend | $6,000 | Their aging report | Cash: fees not charged | Treasury |
| Other hours saved | $54,000 | You measured it: 1,350 hours at $40 | Non-cash: no cost stops | Accounts payable |
Only the cash rows count toward ROI, payback and NPV.
Work out ROI, payback and NPV
Use cash benefits only, and ramp them: nothing lands at full rate on go-live day. State the ramp you used.
ROI
Total cash benefits minus total costs, divided by total costs, over a stated period such as three years.
Payback
The month when cumulative cash benefits overtake cumulative costs.
Net present value
Each year's net cash flow discounted to today at the buyer's hurdle rate or a stated rate, minus upfront costs.
Switching values
For each key assumption, the value at which the deal stops being worth doing. The Green Book asks appraisers to calculate them.
Then take the optimism out. The Green Book describes optimism bias1 as a "demonstrated systematic tendency": costs typically come in higher, benefits lower and delivery later than planned. Bent Flyvbjerg, writing in the Project Management Journal in 2006, recommends reference class forecasting5: basing forecasts on how comparable projects turned out. For you, that means your past customers' rollouts.
If a switching value sits close to your estimate, test that assumption in a proof of concept before anyone signs.
Ask finance for their rates first
Get their discount rate, loaded pay rates and approval threshold before you build. Keep the model in pre-tax cash and say so; how costs are booked or taxed is finance's call.
Write the one-page business case
Many of those 13 stakeholders will never meet you. Give your champion one page they can forward and speak to from memory, with the workings underneath.
The problem, in their words: "We pay a temp agency about $9,000 a month at quarter end just to keep up." (Operations director, May 12)
If nothing changes: $36,000 a year on temps, a clerk hire at $74,000 a year, and about $6,000 a year in late fees despite their new approval rule.
The ask: $4,000 a month, $30,000 to set up, and about 300 hours of their team's time.
The return over three years, cash only: $290,000 in benefits against $186,000 in costs, a 56% ROI. It pays back in month 18, with a net present value of $74,000 at 10%.
What carries it: the planned hire is dropped. Without that, the deal doesn't pay back within three years.
Left out of the headline: another 1,350 hours a year, worth about $54,000, because no cost stops with them.
- Hours counted once. Of 3,200 staff hours saved, only the 1,850 replacing the planned hire count as cash.
- Trend removed. Late fees count only beyond the drop their new rule delivers.
- Their effort costed. Their 300 hours, at $40 an hour, count up front.
- Benefits ramped. Year one counts at half rate.
The inflated version of this deal counts every saved hour as cash from day one, keeps last year's full late fees and drops their effort. It shows a 203% ROI with payback in month 3. That's the version finance takes apart.
Before you send the business case
- Every figure names its source
- Business as usual is costed, trend included
- Their own effort is in the costs
- ROI, payback and NPV use cash benefits only
- Every benefit has an owner
- The assumptions that carry it are named and tested
Working from a pile of call notes? The tool at the top of this page turns them into this case: the register, the three-year model and the one page.
How it works
Start with your discovery notes or a call transcript, and add your price if you have it. River pulls out the figures the buyer gave you and builds the case on them. It notes where each number came from, costs what happens if they don't buy, and counts saved hours as cash only when a cost stops.
You get a one-page case your champion can forward, the full workings beneath it, and a three-year model in a sheet. Where a figure is missing, River makes an assumption, labels it as yours, and shows the case without it. It closes with the payback month, the assumption most likely to be challenged, and one question for you about the buyer figures that would change the answer most.
Paste your discovery notes
Notes, call transcripts or documents the buyer sent, plus your price and their setup effort if known.
River builds the model
It notes each figure's source, costs business as usual, and counts hours as cash only when a cost stops.
Get your business case
A one-page case for the champion, the workings beneath it, and a three-year model in a sheet.
Check it and share
Correct any assumption, rebuild at a smaller scope, or ask River to draft the champion's email.
What you get
- One forwardable page: the problem in the buyer's words, the ask, the cash return and what carries it
- A benefit register showing each figure's source, whether it is cash, and whose budget it changes
- Payback in months and net present value at a stated discount rate, counting cash benefits only
- The cost of carrying on as they are, with any improvement that would happen anyway taken off
- Their own costs priced in: implementation hours, project effort, training time and any parallel running
- A three-year model in a sheet, with the benefit ramp and business-as-usual baseline as separate lines
Common questions
What should a B2B business case include?
It needs the problem in the buyer's own words, the cost of carrying on as they are, and the full cost of buying. Then comes the cash return: ROI, payback month and net present value. Add the assumptions the result rests on, an owner for each benefit, and what you left out. Keep the summary to one page, with the workings attached.
How do you calculate ROI for a business case?
Subtract total costs from total cash benefits over a stated period, then divide by total costs. If a deal returns $150,000 in cash benefits against $100,000 in costs over three years, the ROI is 50%. Include the buyer's own effort in the costs, and ramp benefits up from go-live instead of counting them in full from day one.
Do hours saved count in an ROI model?
They count as a benefit, but not as cash unless they change what the buyer spends or earns. Saved time becomes money when it ends contractor spend or overtime, replaces a planned hire, or moves people onto work that earns revenue. Otherwise, show the hours and their value in a separate non-cash section, outside the ROI and payback.
What if the buyer won't share their numbers?
Build the case on your own assumptions and label each one as yours. It is a weaker document but an honest one, and it gives the champion something concrete to correct. Then ask for real figures on the two or three assumptions that move the answer most. Never present an industry average as their number.
Should a business case be written for the champion or the CFO?
Write for whoever has to be convinced. A champion presenting without you needs one page they can speak to from memory. A CFO or finance team wants the workings first and the summary second. A procurement or investment committee wants the options side by side, including carrying on as they are.
How do I build a business case with River?
Paste your discovery notes or a call transcript into the box at the top of this page, and attach any documents the buyer sent. Add your price if you have it, and pick who has to be convinced. River writes the one-page case, the full workings and a three-year model into your free River workspace, ready to check and edit.
Is the sales ROI calculator free?
Yes, it is free to start. Your business case opens in a River workspace, where you can edit it, share it or ask River to change it. Paid plans add more AI use and access to the most advanced models.
Sources
HM Treasury. “The Green Book (2026).” gov.uk (opens in a new tab)
U.S. Bureau of Labor Statistics. “Compensation costs for private industry workers averaged $46.89 per hour worked in June 2026.” bls.gov (opens in a new tab)
arXiv. “Why Your IT Project Might Be Riskier Than You Think.” arxiv.org (opens in a new tab)
Forrester. “The State Of Business Buying, 2026.” forrester.com (opens in a new tab)
arXiv. “From Nobel Prize to Project Management: Getting Risks Right.” arxiv.org (opens in a new tab)
Built by
Chandler Supple
Co-founder & CEO, River
Chandler has spent the last six years working in AI, building tools for millions of users and Fortune 100 companies. In 2025, he co-founded River to build a new kind of operating system for AI agents.