Is Your Monthly Budget Actually Working?
Pick your state and enter your take-home income and expenses. See your savings rate against the 50/30/20 rule — and the sales tax quietly hidden inside your spending.
Your state
Loads your state's live sales tax rate to estimate the tax inside your spending
Rent/mortgage + utilities
Dining out, shopping, subscriptions — your 'wants'
Leave at 0 to use your state's live combined rate.
Reading your inputs…
Calculating your budget calculator
On a $5,000 budget, $1,700 left over is a 34% savings rate — but ~$940/year of that spending is sales tax most people never see. Housing, not coffee, is the biggest lever.
50/30/20
needs / wants / savings — the rule this calculator benchmarks your budget against
4.6%
actual US personal savings rate (BEA, 2024) — the 20% target is a stretch most people miss
$940/yr
sales tax hidden in the example $5,000 budget at the 7.12% US-average rate
How to actually improve your budget
Housing is the biggest lever
If your housing costs exceed 35% of take-home pay, no amount of latte-cutting will fix your budget. Your largest fixed expense has the largest impact. Even a $200/month reduction in rent saves $2,400/year — more than eliminating coffee, gym, and Netflix combined for most people.
Debt payments kill savings rate
High minimum debt payments are the silent killer of savings rates. A $500/month debt payment on a 22% APR credit card costs $6,000/year with minimal progress on the principal. Prioritising high-interest debt payoff over investing (when rate > 7%) is mathematically sound — use the avalanche or snowball method.
Budget for irregular expenses monthly
Car insurance, annual subscriptions, car registration, and holiday gifts feel like surprises — but they aren't. Divide annual irregular expenses by 12 and set aside that amount each month into a dedicated sinking fund. This eliminates budget emergencies and smooths cash flow.
How the Budget Calculator Works
Formula
Total Expenses = Housing + Food + Transport + Debt + Other
Leftover = Income − Total Expenses
Savings Rate = Leftover ÷ Income × 100
50/30/20 rule:
Needs (housing+food+transport+debt) → target 50% of income
Wants (other / discretionary) → target 30%
Savings (leftover) → target 20%
Sales tax (live): taxable = other + (groceries if state taxes them)
Annual sales tax = taxable × state combined rate × 12
Worked example — $5,000 take-home, US-average 7.12% rate:
Expenses $3,300 · Leftover $1,700 (34% savings rate)
Needs 56% · Wants 10% · Sales tax ~$940/yrThis calculator sums your monthly expenses, subtracts them from take-home pay, and shows your leftover both in dollars and as a savings rate. It then maps your spending onto the 50/30/20 rule — needs, wants, and savings — and flags whichever bucket is out of line. In the default example, needs run 56% (just over the 50% target) while the 34% savings rate is well ahead of the 20% goal.
The clever part is the live sales-tax layer: using your state's combined rate (Tax Foundation 2026), it estimates the tax baked into your taxable spending — discretionary goods plus groceries in states that tax them. On the $5,000 example that's about $940/year you never see itemised. Choose a grocery-exempt state and food automatically drops out of the taxable base.