Free Calculators for Finance, Health, and Business

Sliders, live chart, optional local save of your inputs.

Purchasing-power decay vs CPI, Rule of 72 context, optional return line and year-by-year chart.

Kelly vs half vs quarter vs fixed-risk sizing: table, KPI row, and comparison chart, private and client-side.

Modeled pacing vs lump-sum with volatility corridor chart, illustrative assumption-driven math only.

Dynamic asset and liability rows, donut and category charts, session-only, never transmitted.

FIRE number, years to independence, path chart, and savings-rate sensitivity, localStorage inputs.

Minimum vs fixed payments vs payoff-by-date, balance chart and interest totals.

Multiple debts, extra budget, months, interest, payoff order, and chart for both strategies.

Amortization table, PMI and escrow, prepayments, CSV export.

Federal brackets and optional state tax, after-tax projection chart vs Traditional.

Monthly payment, total interest, and amortization from principal, rate, and term.

Extra principal each month, months and interest saved vs minimum payment.

Fixed costs, variable cost per unit, and selling price to find break-even units and revenue.

Net profit and cost of investment to ROI percentage, return multiple, and optional annualized ROI.

Calculate the real cash value of airline miles and points across major loyalty programs.

Monthly essentials × coverage minus cash on hand, with a grounded month-by-month fill plan.

Federal, state, FICA, and pre-tax benefits, net pay per check for 2026.

2025/26 Income Tax, NI, pension, and student loan, net pay with donut breakdown.

FY 2025-26 FBR slabs, EOBI, provident fund, salaried and freelancer modes with effective tax rate.

Trinity-style safe withdrawal, year-by-year depletion, SS offset, and multi-rate comparison.

Break-even age and NPV, monthly pension vs invested lump sum with COLA and return sensitivity.

Total interest and closing costs side-by-side, find when refi pays back its closing costs.

Find the year buying beats renting, interactive graph with your assumptions.

COGS, shipping, payment fees, refunds, minimum ROAS to cover variable costs.

USD fees from the 2026 Q2 excerpt, referral floor, fulfillment ladder, per-unit KPIs, horizon multiply.

Per-order profit after 2026-style Etsy fees, transaction on price + shipping charged, US processing, Offsite Ads toggle.

Basic vs Shopify vs Advanced net at your volume, 2026 plan fees, Shopify Payments or third-party stack, apps, and CAC per order.

E-commerce vs subscription LTV, CAC, payback months, health bands, and one-step churn or frequency sensitivity.

POD profit after fees and shipping, break-even price, stacked breakdown, Printful vs Printify vs MBA.

Free shipping, upsell, and bundle levers, new AOV, monthly revenue lift, and gross profit by tactic.

Turnover, days on hand, holding cost, and cash freed when you hit a target turnover rate.

Cost to wholesale to retail chain, markup vs margin, keystone badges, reverse from any tier.

Calculate selling price and gross profit from cost and markup percentage. Understand markup vs margin.

Minimum rate from take-home goals, taxes, expenses, and billable hours.

Tier cards with effective hourly, below-rate warnings, deliverable rows, and capacity bar chart.

Dynamic phase rows, fixed-price toggle, totals block, blended rate KPI, and copy quote for proposals.

Three modes: hourly to annual, annual to hourly, freelance vs salaried with SE tax, benefits, and PTO value.

Overdue invoice interest, simple or compound, accumulation chart, jurisdiction notes, demand copy.