What does Prosper simulate each year?
Each year, Prosper updates income, spending, debt payments, and asset growth. If spending is higher than income, it covers the gap using your Spending Order.
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Prosper Prosper 
Plan retirement, optimize mortgages, and simulate your net worth - privately, on your device.
See your cashflows and allocations at a glance.
See how extra payments cut interest and shorten your payoff timeline.
See how major decisions shift your future net worth before they happen.
Use Prosper directly in your browser — no install required. Full planning workspace on any desktop.
Prosper helps you plan retirement, mortgage decisions, and net worth evolution with scenario-based simulation.
Simulate Future Net Worth
Configure salary, costs, pension, and allocations to project net worth over time.
Monte Carlo Simulation
Run thousands of randomized scenarios to model market uncertainty and visualize a range of possible outcomes.
Advanced Planning Controls
Refine salary raises and cost-of-living changes year by year across your entire life timeline.
Custom Entries
Add assets, liabilities, and custom cashflows with value appreciation or depreciation rules.
Household Profiles
Create multiple profiles and aggregate the household outlook in a single simulation.
Tools
Run dedicated mortgage payoff and compound growth simulations.
Need more detail before installing? Visit the full FAQ and How It Works page.
Build your profile, run scenarios, and compare outcomes before making major financial decisions.
Configure your baseline
Enter salary, costs, retirement age, and expected growth to establish your foundations.
Add assets and liabilities
Model mortgages, financed assets, savings, investments, and custom cashflows.
Compare realistic scenarios
Save snapshots, stress assumptions, and validate plan sustainability.
Start from the scenario that matters most, then branch into deeper modeling.
Plan retirement with fewer blind spots
Estimate when your current plan becomes sustainable by testing best, base, and stress scenarios.
Optimize mortgage payoff strategy
Compare amortization options and see how extra payments change total cost and payoff date.
Understand compound growth outcomes
Simulate contributions and long-term growth assumptions to visualize expected net worth ranges.
See how the simulation logic works before you install.
Each year, Prosper updates income, spending, debt payments, and asset growth. If spending is higher than income, it covers the gap using your Spending Order.
Read more →When yearly spending is higher than yearly income, Prosper uses your Spending Order to cover the gap. This tells the app what to use first, such as cash, savings, investments, or sellable assets. If one source is not enough, it automatically moves to the next.
Read more →Taxes are applied only when assets are sold, such as for spending or required liquidation. Unrealized gains are not taxed. Taxes are off by default until you configure and enable them.
Read more →Standard taxes gains using your global tax rate. Tax-Free applies no tax on sale. Custom taxes gains using a custom rate for that asset. Tax-Deferred taxes the full withdrawn amount instead of only the gain.
Read more →Cost basis is what you originally paid for an asset. Prosper uses it to estimate how much of a sale is profit, so taxes can be calculated more realistically. If you leave it blank, the app uses the asset value at the time you created it.
Read more →Usually no. In many countries, savings interest is taxed when the bank credits it, not when you withdraw it. The savings growth rate you enter should already reflect that.
Read more →Free to download. No account required. Your data stays on your device by default.