How the numbers work

How we calculate

Clear assumptions for every Nestfigure calculator. Estimates for learning—not bank quotes or advice.

How we calculate

How the CD calculator works

How we estimate CD interest, what APY means in the tool, compounding choices, optional monthly deposits, and what we leave out (penalties, fees, taxes).

Read how it works → Open tool: CD Calculator
How we calculate

How the raise calculator works

How we turn a raise percent or dollar amount into new annual, monthly, biweekly, and weekly pay—and optional rough tax views.

Read how it works → Open tool: Raise Calculator
How we calculate

How the credit card payoff calculator works

How we estimate months and interest from balance, APR, and payment plan—and what we leave out (fees, promo rates, real issuer minimums).

Read how it works → Open tool: Credit Card Payoff
How we calculate

How the overtime calculator works

How we estimate regular, OT, and double-time pay from rate, hours, and multipliers—and what we leave out (legal eligibility, taxes).

Read how it works → Open tool: Overtime Calculator
How we calculate

How the paycheck calculator works

How we split gross by pay frequency and apply a tax rate you type—and what we leave out (IRS tables, state engines).

Read how it works → Open tool: Paycheck Calculator
How we calculate

How the loan calculator works

How we estimate installment payments and interest from principal, APR, and term—and what we leave out (fees, variable rates).

Read how it works → Open tool: Loan Calculator
How we calculate

How the student loan calculator works

How we estimate fixed-rate student loan payments and interest—and what we leave out (IDR, forgiveness, live rates).

Read how it works → Open tool: Student Loan Calculator
How we calculate

How the auto loan calculator works

How we build amount financed from price, down payment, trade-in, tax, and fees, then amortize—and what we leave out.

Read how it works → Open tool: Auto Loan Calculator
How we calculate

How the savings goal calculator works

How we estimate months to a savings target with monthly deposits and an APY input—and what we leave out (fees, live rates).

Read how it works → Open tool: Savings Goal Calculator
How we calculate

How the compound interest calculator works

How we estimate future value from principal, rate, years, compounding, and optional deposits—and what we leave out.

Read how it works → Open tool: Compound Interest Calculator
How we calculate

How the simple interest calculator works

How we estimate I = P × r × t on principal only, year schedules, and a simple-vs-compound contrast—and what we leave out.

Read how it works → Open tool: Simple Interest Calculator
How we calculate

How the ROI calculator works

How we estimate total return on investment and optional annualized return—and what we leave out (fees, forecasts).

Read how it works → Open tool: ROI Calculator
How we calculate

How the 401(k) calculator works

How we estimate employee deferrals, a sample employer match formula, and optional growth—and what we leave out.

Read how it works → Open tool: 401(k) Calculator
How we calculate

How the break-even calculator works

How we estimate break-even units and revenue from fixed costs, price, and variable cost—and what we leave out.

Read how it works → Open tool: Break-Even Calculator
How we calculate

How the savings duration calculator works

How we estimate months of runway from balance, fixed monthly withdrawals, and optional constant growth—and what we leave out.

Read how it works → Open tool: How Long Will Savings Last
How we calculate

How the inflation calculator works

How we estimate future cost and past value with a constant average inflation rate—and what we leave out (live CPI tables).

Read how it works → Open tool: Inflation Calculator
How we calculate

How the debt-to-income calculator works

How we estimate front-end and back-end DTI from gross income and monthly debts—and what we leave out (underwriting rules).

Read how it works → Open tool: Debt-to-Income Calculator
How we calculate

How the mortgage calculator works

How we estimate principal and interest from home price, down payment, rate, and term—and what we leave out (PMI, live rates).

Read how it works → Open tool: Mortgage Calculator
How we calculate

How the mortgage refinance calculator works

How we compare current vs new payments, interest, and break-even on closing costs—and what we leave out.

Read how it works → Open tool: Mortgage Refinance Calculator
How we calculate

How the biweekly mortgage calculator works

How we compare monthly and biweekly amortization, interest saved, and time saved—and what we leave out.

Read how it works → Open tool: Biweekly Mortgage Calculator
How we calculate

How the 50/30/20 budget calculator works

How we allocate take-home into needs, wants, and savings shares, optional actuals, and what we leave out.

Read how it works → Open tool: 50/30/20 Budget Calculator
How we calculate

How the tip calculator works

How we estimate tip, total with tip, pretax tip base, and even splits—and what we leave out.

Read how it works → Open tool: Tip Calculator
How we calculate

How the emergency fund calculator works

How we build a target from expenses × months, months covered, shortfall, and what we leave out.

Read how it works → Open tool: Emergency Fund Calculator
How we calculate

How the net worth calculator works

How we sum assets and liabilities, compute net worth and debt-to-asset ratio—and what we leave out.

Read how it works → Open tool: Net Worth Calculator
How we calculate

How the percent-off calculator works

How we compute discount, sale price, optional tax after discount, and quantity totals—and what we leave out.

Read how it works → Open tool: Percent Off Calculator
How we calculate

How the commission calculator works

How we estimate commission from sales and rate, optional base and draw—and what we leave out.

Read how it works → Open tool: Commission Calculator
How we calculate

How the hourly to salary calculator works

How we convert hourly rate, hours/week, and weeks/year to annual and period pay—and what we leave out.

Read how it works → Open tool: Hourly to Salary Calculator
How we calculate

How the sales tax calculator works

How we add tax to pretax or reverse a total with tax—and what we leave out (no live ZIP rates).

Read how it works → Open tool: Sales Tax Calculator
How we calculate

How the home affordability calculator works

How we estimate max home price from income, sample DTI caps, reverse amortization, and down payment—and what we leave out.

Read how it works → Open tool: Home Affordability Calculator

Who builds this

Content and tools are published by Nestfigure and maintained by John Rey Balais. Full bio: About Nestfigure.

Important note

Nestfigure is not a bank, broker, employer, or adviser. Calculator results are educational estimates under documented formulas. Deposit topics cite CFPB, FDIC, and NCUA materials where relevant; wage context cites BLS; withholding context cites IRS Publication 15-T. We do not invent rates, averages, or credentials.

YMYL notice: This site is for education only. It is not financial, tax, or investment advice. Nestfigure is not a bank, credit union, broker, investment adviser, or fiduciary. Product terms, rates, and penalties vary—always read your institution’s disclosures before acting. Calculator results are mathematical estimates, not bank quotes.