Business Idea Score Calculator
Updated
This page has a free business idea score calculator and the exact formula behind it. You rate an idea on five factors, say how well the evidence backs your ratings, and get one number. The same formula ranks the daily idea Proofline publishes, so you can score your own idea against the ones on the leaderboard.
What the calculator does
It turns a gut feeling into a number you can argue with. You enter five ratings and one evidence level. It applies fixed weights, adds the results, and scales the total by the evidence multiplier. Nothing is hidden: every step is on this page, and you can reproduce the output with a pencil.
It does not research your market, check your competitors, or tell you whether to quit your job. It ranks ideas against each other using your own judgment, adjusted for how much proof you have.
The formula
Score = (Pain × 0.30 + Why-now × 0.25 + Revenue × 0.20 + Open market × 0.15 + Ease × 0.10) × Evidence
The five weights add up to 1.00, so the weighted sum stays on the same scale as your inputs. The evidence multiplier then sits between 0.70 and 1.00.
| Factor | Weight | The question it answers |
|---|---|---|
| Pain | 0.30 | How badly do specific people want this fixed, and what do they do about it today? |
| Why-now | 0.25 | What changed recently that makes this possible or urgent? |
| Revenue | 0.20 | Is there a believable way to charge, and do buyers already spend money nearby? |
| Open market | 0.15 | Is there room, or is one incumbent sitting on the whole category? |
| Ease | 0.10 | Could a small team build and sell a first version without heroic effort? |
Why pain gets the biggest weight
Plenty of products are easy to build and pleasant to use that nobody needed. A painful problem survives bad design, slow sales and a thin feature set. So pain carries 0.30, three times the weight of ease.
Why-now sits second
A real problem that has existed for ten years and never produced a company usually has a reason. Timing is that reason. A new regulation, a platform change, a cost drop or a shift in buyer habits can open a door that was shut last year. If you can't name the change, the idea scores low here, and it should.
Why ease is last
Ease matters, but it is the factor founders overrate. A hard build with a severe pain point beats a trivial build for a shrug. Ease at 0.10 breaks ties more than it decides outcomes.
What the evidence multiplier does
Your ratings are claims. The multiplier discounts them when you haven't backed them up. At 1.00 your ratings count in full. At 0.70 they lose 30%. A founder who has talked to buyers, seen them pay for workarounds, and can point to comparable companies should sit near the top of that range. Someone working from a hunch should sit near the bottom. The full scoring method is on the methodology page.
How to use it
- Write the idea in one sentence. Name the buyer, the problem, and what you'd sell. "Shift-swap tool for home care agencies" is scoreable. "AI for healthcare" is not.
- Rate pain first. Think of an actual person who has the problem. What do they do now? Spreadsheets, a paid contractor and a lot of phone calls suggest a high rating.
- Rate why-now. Write the specific change down. If you can't, be harsh.
- Rate revenue and open market. Look for products people already pay for in the space. Payment nearby is a good sign. A crowded category with a dominant player lowers open market.
- Rate ease last. It's the one that tempts you to start with, so leave it until the end.
- Pick the evidence level. Be conservative. Reading articles about a market is weaker than a buyer telling you they'd switch.
Example input and output
These two ideas are made up, and the numbers are illustrative arithmetic, not real products. They use a 0–10 scale so the math is easy to follow; the fields in the tool show the range it accepts.
| Idea A | Idea B | |
|---|---|---|
| Pain | 8 | 5 |
| Why-now | 6 | 9 |
| Revenue | 7 | 6 |
| Open market | 5 | 8 |
| Ease | 4 | 9 |
| Weighted sum | 6.45 | 7.05 |
| Evidence multiplier | 0.85 | 0.70 |
| Final score | 5.48 | 4.94 |
Idea A: 8×0.30 = 2.40, 6×0.25 = 1.50, 7×0.20 = 1.40, 5×0.15 = 0.75, 4×0.10 = 0.40. That totals 6.45, and 6.45 × 0.85 = 5.48.
Idea B: 1.50 + 2.25 + 1.20 + 1.20 + 0.90 = 7.05, and 7.05 × 0.70 = 4.94.
On raw ratings, B wins. With evidence applied, A wins, because its founder has more proof behind the pain rating. That flip is the reason the multiplier exists. It also shows the cheapest way to raise a score: go get evidence. Re-rating the same idea more generously doesn't help much, and you'll know you did it.
Limits you should know about
- Garbage in, garbage out. The calculator multiplies and adds. If you rate pain 9 because you personally find the problem annoying, you get a confident-looking number built on one data point.
- The weights are a judgment call. They reflect how Proofline thinks about early-stage ideas. A founder with a deep technical edge might reasonably weight ease higher. Change the weights on paper and see whether your ranking survives.
- It compares; it does not predict. A 6.5 is not a 65% chance of success. Use it to rank a shortlist, not to approve one idea.
- It can't see what you don't tell it. Distribution, founder fit, timing inside your own life and regulatory risk are outside the formula.
- Close scores are ties. A gap of a few tenths between two ideas is within the noise of your own ratings.
Where this comes from
Weighted scoring for ideas isn't new. ICE scoring was popularized by Sean Ellis and Morgan Brown, and RICE came out of Intercom. Both were built to rank product work, such as features and growth experiments. Proofline's version is aimed at a different question: whether a new business idea is worth starting. That is why it asks about timing, buyers and market structure instead of reach and effort. If you're prioritizing a roadmap, ICE or RICE is likely a better fit than this.
What to do with your score
Score three to five ideas, not one. Then look at how published ideas are rated: today's pick is on the daily idea page, and past ones are in the ideas archive. A full example with comparables is shift swaps for home care. If you're weighing Proofline against other idea sources, the comparison pages go through the differences, including where others are stronger. If an idea scores well and you want to act on it, the build page is the place to go next.
Sources
Frequently asked questions
What is a business idea score calculator?
It combines your ratings of an idea's key factors into one number so you can compare ideas. Proofline's version rates pain, why-now, revenue, open market and ease, then multiplies by an evidence factor.
What is the formula?
Score = (Pain × 0.30 + Why-now × 0.25 + Revenue × 0.20 + Open market × 0.15 + Ease × 0.10) × Evidence, where Evidence runs from 0.70 to 1.00.
Why does the evidence multiplier go no lower than 0.70?
It discounts unsupported ratings by up to 30% without wiping them out. An idea with little proof still scores, but it ranks below an equally rated idea that has been checked with real buyers.
Does a high score mean my idea will succeed?
No. The score ranks ideas against each other using your own ratings. It does not predict outcomes, and it ignores factors like founder fit, distribution and regulatory risk.
How is this different from ICE or RICE scoring?
ICE and RICE are made for prioritizing product work. This formula asks whether a new business is worth starting, so it covers timing, willingness to pay and market structure instead of reach and effort.
Can I change the weights?
The calculator uses fixed weights. You can apply your own weights by hand with the formula above and check whether your ranking of ideas still holds.