Methodology
Calculator methodology
Spendika calculators are planning tools. They use the values entered on the page and do not perform currency conversion or personalised advice.
Monthly Budget Calculator
Income minus fixed bills, flexible spending, debt payments and planned savings.
Values are rounded for display. Results are estimates and should be reviewed against real statements, bills and circumstances.
Savings Goal Calculator
Remaining target divided by months to target, with months clamped to at least one.
Values are rounded for display. Results are estimates and should be reviewed against real statements, bills and circumstances.
Emergency Fund Calculator
Essential monthly costs multiplied by the chosen number of months of cover.
Values are rounded for display. Results are estimates and should be reviewed against real statements, bills and circumstances.
Debt Repayment Calculator
Monthly interest is estimated from APR divided by twelve, then payments are applied until the balance reaches zero.
Values are rounded for display. Results are estimates and should be reviewed against real statements, bills and circumstances.
Subscription Cost Calculator
Weekly subscriptions are annualised over 52 weeks, then combined with monthly and yearly costs.
Values are rounded for display. Results are estimates and should be reviewed against real statements, bills and circumstances.
Car Cost Calculator
Monthly finance, insurance, fuel, maintenance, tax and parking are summed and annualised.
Values are rounded for display. Results are estimates and should be reviewed against real statements, bills and circumstances.
Holiday Budget Calculator
Trip costs plus daily spending plus a simple emergency allowance, minus current savings.
Values are rounded for display. Results are estimates and should be reviewed against real statements, bills and circumstances.
Last reviewed: 19 September 2026.