Plain Finance Tools
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Clearer financial decisions start here

Make the
next step
with confidence.

Free calculators for loans, savings goals, CDs, and compound growth. See your numbers, understand the trade-offs, and move forward with a plan.

  • Free tools
  • No signup
  • Your numbers stay in your browser

From a calculation to a decision

A simple process.
Real progress.

Go from a question to a clearer plan. Explore your numbers, understand the assumptions, and choose your next step.

  1. Run the numbers

    Use a focused calculator with clear inputs and helpful examples.

  2. Understand your options

    See how changing an assumption changes the result.

  3. Take your next step

    Compare scenarios or keep a record of your plan.

Focused calculators

Start with the result you need. Every calculator connects to its formula, limitations, examples, and related guides.

View the calculator directory
Borrowing

Loan calculator

Estimate a fixed monthly payment, total interest, payoff time, and the effect of recurring extra principal.

  • Monthly payment
  • Amortization schedule
  • Extra-payment comparison
Calculate a loan
Fixed-term saving

CD calculator

Estimate maturity value and interest from a deposit, APY, and term, or compare two certificate offers.

  • Maturity value
  • Offer comparison
  • Interest milestones
Estimate CD earnings

Independent tools. Shared progress.

Built independently.
Made to help you grow.

Managing your financial future shouldn't require expensive software or complicated spreadsheets.

That's why I'm building simple, accessible financial tools to help people plan their savings and understand compound growth.

Our calculators are completely free. If you find them useful, purchasing our $15 Savings & Growth Workbook gives you more powerful planning tools while supporting the development of new free resources.

Explore the workbook
Preview of the workbook's scenario comparison worksheetCompare scenarios. Keep your plan.
See the 58-second workbook tour →

Explore by goal

Learn the concept. Test the scenario.

Each collection brings the calculator and educational material into one practical path.

03

Certificates of deposit

Compare fixed-term deposit assumptions

Estimate maturity value, separate deposit from interest, and compare APY, term, and opening balance.

Start with the fundamentals

Financial guides built around the numbers.

Concise explanations, worked examples, and source notes designed to make calculator results easier to interpret.

Browse all financial guides

Free planning resource

Put a clear question behind the numbers.

Use our scenario-planning checklist to record assumptions, compare one change at a time, and understand the limits of an estimate.

Explore planning resources →

Built for scrutiny

A useful estimate should show its assumptions.

Plain Finance Tools separates inputs, deposits, interest, and limitations so you can explain why a result changes.

Review our methodology
  1. 01
    Your numbers stay private

    Calculations run locally in your browser and financial values are excluded from analytics.

  2. 02
    The method is inspectable

    Formulas, timing assumptions, rounding rules, and examples are documented.

  3. 03
    Estimates stay estimates

    Results are educational scenarios, with exclusions and limitations stated clearly.

Help shape what comes next

Help us build more free financial tools

Our tools are free because we believe everyone deserves access to simple financial planning.

If they've helped you, consider supporting this independent project. Every contribution helps us maintain existing tools and develop new ones.

Choose how you'd like to support us.

Voluntary contributions

Choose a one-time contribution on Buy Me a Coffee. You can select a suggested amount or enter your own.

Support on Buy Me a Coffee Supporting us is optional. Our calculators stay free. Contributions do not purchase the workbook.Opens Buy Me a Coffee, where you choose the amount and complete payment. No calculator values are shared.

Your ideas help, too.

Tell us what works, what needs fixing, or what you'd like to calculate next.