Quick Tools
Free, single-purpose calculators that run in your browser. No accounts, no payments, nothing stored on a server. Pick a tool and get an answer in the page.
Salary Increase Calculator
See new yearly, monthly, biweekly, and hourly pay after a raise.
Open tool →High School GPA Calculator
Weighted and unweighted 4.0 GPA from your courses, credits, and level.
Open tool →HELOC Calculator
Estimate max line, remaining equity, and HELOC interest or P&I payments.
Open tool →CD Interest Rate Calculator
Certificate-of-deposit interest calculator with APY/APR and compounding frequency. For people comparing bank CD offers. Not a bank, not tax advice, not a rate lock.
Open tool →Percentage Calculator
Find X% of Y, what percent one number is of another, percent change, and an optional percent table.
Open tool →JSON Formatter
in-browser JSON pretty-printer, minifier, and syntax validator.
Open tool →Concrete Calculator
Cubic yards, cubic feet, and 60- or 80-lb bag counts for slabs, footings, and columns.
Open tool →Markup Calculator
Convert cost and markup into selling price, profit per unit, and gross margin.
Open tool →Amortization Calculator
Monthly P&I payment plus a year-by-year principal vs interest schedule.
Open tool →Ovulation Calculator
Estimate ovulation and a six-day fertile window from last period and cycle length.
Open tool →Mortgage Payoff Calculator
Add extra monthly or lump-sum payments to see a new payoff date and interest saved.
Open tool →Mortgage Refinance Calculator
Compare your current mortgage to a refinance: new payment, interest, and break-even.
Open tool →Personal Loan Calculator
Monthly payment, total interest, and a payoff schedule for unsecured personal loans.
Open tool →Barcode Generator
Encode a SKU or number as Code 128, Code 39, EAN-13, or UPC-A and download PNG or SVG.
Open tool →Tip Calculator
Tip amount, total bill, and a per-person split from bill and percent.
Open tool →Square Footage Calculator
Length × width for rooms in feet, inches, or meters, plus sq ft ↔ sq m.
Open tool →Student Loan Calculator
Monthly payment, total interest, and payoff date from remaining balance, APR, and term.
Open tool →Overtime Calculator
Time-and-a-half, double-time, and weekly gross from hourly rate and overtime hours.
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