Rule of 72 Wealth Planner
Show how long investments could take to double and visualize long-term growth.
The simplest useful piece of investing arithmetic, made visual: how long money takes to double at a given return, and what that means across a working life. Small, fast, and hard to argue with.
What a v1 does5 features
- Doubling time calculated for any rate and sum
- The effect of starting five years earlier, shown side by side
- Real returns after inflation as well as nominal
- Multiple goals tracked on one chart
- Shareable projections without any account needed
The market
No portfolio tracker publishes revenue or user numbers, so price is the only available evidence. Sharesight charges $24 and Snowball Analytics $299 for professional use. At $4 a month this sits below both.
Where these numbers come from
| Company | Earns | Reach | Source |
|---|---|---|---|
| Sharesight | $24/mo Premium | Hundreds of thousands of investors, 100+ countries | Published pricing |
| Snowball Analytics | $12.50 per 10 portfolios · $299/mo pro | Not published | Published pricing |
| Empower | Wealth-management upsell | Not published | Model, not a disclosed figure |
Why this audience
This audience likes named, teachable pieces of arithmetic - that is the shape of the content. The doubling rule is one they have almost certainly met here. Making it visual against their own numbers turns a lesson into a planning tool.
Before it can launch
No licence, certification or data agreement stands between this and a launch — app-store review and an ordinary privacy policy aside.
What it earns
Drag me Every figure recalculates as you go.
0.0047% of 21.2M followers · capped at 50,000
Opens on the price this idea was costed at, $4.
1,000 paying — 0.0047% of 21.2M followers — × $4 a month = $4,000 a month
Fifty thousand paying users is the ceiling every one of these pages is drawn against, not a forecast. It opens at a thousand, the bottom of the range, so the first figures you see are the modest ones. What the cap buys is comparability: the same range on every app, and the percentage of the audience it takes as the number that moves.
Is this the one for your audience?
We fund it, build it, and run it. You bring the audience and take a share of the revenue. Nothing to pay and nothing to build.
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