Tool

The free budget calculator that keeps working after day one

One-time calculators tell you a number and then you are on your own. A free budget tool that lives on a calendar tells you the number, then updates it every time life changes — which is weekly. This guide covers the calculations that matter and where to do them for free.

Use the free calculator

  • The core four

    Income, fixed costs, variable average, saving margin — the only numbers that matter.

  • Lives on a calendar

    Free, recurring, and always projecting forward instead of describing the past.

  • No bank linking

    The safest free option: enter what you know, nothing is connected.

  • Updates itself

    Change one bill and every future balance recalculates.

The free calculations that matter

CalculationFormulaWhy it matters
Saving marginIncome − fixed − variableThe number you automate
RunwayBalance ÷ monthly burnDays until zero
Debt payoffBalance ÷ (payment + interest)Months until free
Dated low pointDay-by-day balanceThe overdraft predictor

Free vs paid: what the price actually buys

  1. Free tools cover income, bills, recurring plans and projections — enough for most households.
  2. Paid tiers typically add AI analysis, multi-workspace and unlimited horizon.
  3. Buy the paid tier only when the free version is already a habit, not to fix a motivation problem.

The privacy argument for free

Free tools that require bank credentials are not really free — they monetize your data. A calculator you fill in yourself, stored under your account with no aggregation, is the only version where "free" has no asterisk.

Frequently asked questions

Is there a truly free budget calculator?

Yes. Cashflow Calendar's core — calendar, recurring plans, projections and budget goals — is free forever with no bank linking.

What numbers should a budget calculator ask for?

Starting balance, income, fixed costs, and a conservative variable-spending average. Anything more is optional.

How is a free calculator different from a free trial?

A trial expires; free features do not. Check that the core stays usable before entering any data.

Can I use it without an account?

Yes — guest mode works fully offline, and data syncs if you sign up later.

Free forever, private by design

No bank linking, no data selling, no trial clock.

Open Cashflow Calendar