DIY Cost Tools
Budget Calculator
FINANCIAL CALCULATOR
Add monthly income and planned categories to see total allocations, money remaining, savings rate, and a simple 50/30/20 reference.
Total planned$5,250.00
Money remaining$750.00
Planned savings rate10.0%
50/30/20 savings + debt reference$1,200.00
How it works
The calculator totals monthly allocations, subtracts them from after-tax income, and compares savings plus debt capacity with a 20% reference.
Formula
Remaining income = after-tax income − all planned categories
Savings rate = planned savings ÷ after-tax income
Important limits
- The 50/30/20 approach is only a reference and may not fit every household or location.
- Irregular expenses should be converted to monthly sinking-fund amounts.
- Debt strategy and emergency savings needs depend on individual circumstances.
Frequently asked questions
What does a negative remainder mean?
Planned allocations exceed the monthly income entered.
Should annual bills be included?
Yes. Divide each annual bill by 12 and budget that amount monthly.
Review notes
The tool keeps every input visible and uses after-tax income for a practical monthly view. Last reviewed September 30, 2026.