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This is the future home of the DaveSave app.

DaveSave
Retirement Saving & Spending Calculator

   Available December 2025

Why DaveSave?

DaveSave is an app I wrote after being dissatisfied with all the retirement calculators out there.

Other calculators were either too simple (fixed rates and unrealistic estimates), too complex (too many inputs and too much focus on pretty graphs), or too expensive (I'm not paying $100 a year for a calculator).

So I wrote DaveSave, a tiny app that performs exceptionally accurate calculations, is easy to install & uninstall, and does not share your information—all calculations are done locally on your device.

What DaveSave Is

• Useful Precisely estimate how much you can spend each year and still make your savings last. Find your optimal social security age. Determine how long you can stay retired. Calculate the investment return needed to make your plan work. And more...
• Hard Core Performs up to 2 billion Monte Carlo simulations of your plan. Other professional Monte Carlo calculators use as few as 300.
• Accurate Generates statistically accurate Gaussian-distributed values for inflation and investment return using a fast efficient Marsaglia Polar method. For 2 billion runs, with 35 years of calculations each run, with variable inflation and investment return, that's 140 billion unique random numbers generated. No other retirement calculator does that.

What DaveSave Is Not

• Not a Tax Manager Tax laws are complex, vary by jurisdiction, and change frequently. DaveSave is not intended to estimate, calculate, or manage your taxes. A simple tax-rate feature may be added in the future, but the app is not a tax solution.
• Not a Financial Advisor This app is an educational tool to help you explore retirement ideas. It is not financial, investment, tax, or legal advice. Always consult a qualified professional before making financial decisions.
• Not Guaranteed I’m not a fan of legalese, but this is important. In my testing and regular use, the app has worked accurately for me. But despite rigorous testing, I am one developer and cannot guarantee results for everyone. The software is provided “as is,” without warranties, express or implied. I do not guarantee the accuracy, completeness, reliability, or fitness for any particular purpose. You assume all risk for decisions made using this app, and I am not liable for any losses or damages arising from your use of the app.

How To Use DaveSave

SAVING

1. Enter what you know:
   • beginning balance $
   • current age
   • investment return %
   • investment variability % (i.e. standard deviation)
   • and so on...
2. Click the button next to the thing you want to solve for:
   • final savings balance $
   • investment return %
   • beginning balance $
   • and so on...
3. Watch the app work:
   • Calculates every year of your plan from beginning to end.
   • For each year, it generates a unique value for investment return and applies it.
   • After completing every year of your plan (one simulation run) it then repeats the process for the next simulation run.
   • It will run as many complete simulations of your plan as you tell it to run (default is 100,000 but you can set it for as many as 2 billion).
   • Once complete, you will see the median and average final balances, as well as the calculated value you asked it to solve for.

SPENDING

1. Enter what you know:
   • beginning balance $
   • current age
   • beginning retirement age
   • final retirement age (SSA.gov has a life expectancy calculator here)
   • beginning Social Security age
   • and so on...
2. Click the button next to the thing you want to solve for:
   • beginning balance $
   • beginning age
   • final age
   • optimal beginning Social Security age
   • investment return %
   • and so on...
3. Watch the app work:
   • Calculates every year of your plan from beginning to end.
   • For each year, it generates unique values for inflation and investment return, adds your pension and Social Security, subtracts your spending, applies your investment return, and calculates the ending balance for that year.
   • After completing every year of your plan (one simulation run), it then remembers if that run passed (positive balance) or failed (negative balance).
   • It will run as many complete simulations of your plan as you tell it to run (default is 100,000, but you can set it for as many as 2 billion).
   • Once complete, you will see the median and average final balances, the Probability of Success %, and the calculated value you asked it to solve for.