A 50/30/20 Budget Tracker in Google Sheets, Formula by Formula
The 50/30/20 rule splits take-home income into needs, wants, and savings/debt, roughly in a 50%, 30%, 20% ratio. Whether that split fits your situation is a separate question. What it gives a spreadsheet is three categories to tag transactions against and measure against a target, and that’s what this post builds.
Sheet layout
Two tabs: Transactions for raw entries, Summary for the rollup. Add a
transaction and nothing else needs to change, because the formulas live on
a different tab.
Transactions columns:
| Date | Description | Amount | Category |
|---|---|---|---|
| 2026-08-01 | Rent | 1400 | Needs |
| 2026-08-02 | Streaming | 15 | Wants |
| 2026-08-03 | 401k transfer | 300 | Savings |
Restrict Category to a dropdown with Data → Data validation → Dropdown
(Needs, Wants, Savings). The rollup formulas below match against
these strings exactly, so a typo in a manually-typed category breaks the
totals silently.
The rollup formulas
On Summary, with income in B1:
=SUMIF(Transactions!D:D, "Needs", Transactions!C:C)
=SUMIF(Transactions!D:D, "Wants", Transactions!C:C)
=SUMIF(Transactions!D:D, "Savings", Transactions!C:C)
Each scans the full column regardless of row count, so new transactions don’t require touching the formula.
As a percentage of income:
=SUMIF(Transactions!D:D, "Needs", Transactions!C:C) / B1
Format the cell as a percentage rather than multiplying by 100 by hand. That keeps the underlying value a true fraction, which matters if you chart it later.
A progress bar without a chart
SPARKLINE renders a small horizontal bar inline in a cell:
=SPARKLINE(B2/B1, {"charttype","bar";"max",0.5})
B2 is the Needs total, 0.5 is 50% as a fraction. The bar fills relative
to that max, so it visually clips right at the target ratio instead of
scaling to whatever the current value happens to be.
Flagging over-target categories
Conditional formatting, custom formula:
=B2/$B$1 > 0.5
Set the highlight color and this flags the Needs percentage the moment it crosses 50%. No manual checking required.
Categories that don’t fit cleanly
Real spending rarely sorts into three clean buckets. A phone bill is partly a need and partly discretionary. The formulas above don’t care about that ambiguity; they only need every row to have some value in Category. Pick a tie-breaking rule once, apply it consistently, and remember the SUMIF totals are only as meaningful as the categorization behind them.
The same pattern, raw log plus dropdown-constrained categories plus SUMIF rollups, works past three categories too. A six-category zero-based budget uses the same structure with more rows on the Summary tab.