OnSumo Tools
Interactive calculators built for speed, privacy, and clarity. Each tool runs in your browser unless we say otherwise.
Finance
Interest, loans, mortgages, and money growth calculators.
- Compound interest calculator
Sliders, live chart, optional local save of your inputs.
- Inflation impact calculator
Purchasing-power decay vs CPI, Rule of 72 context, optional return line and year-by-year chart.
- Position sizing calculator (Kelly)
Kelly vs half vs quarter vs fixed-risk sizing: table, KPI row, and comparison chart, private and client-side.
- Dollar-cost averaging (DCA) calculator
Modeled pacing vs lump-sum with volatility corridor chart, illustrative assumption-driven math only.
- Net worth tracker
Dynamic asset and liability rows, donut and category charts, session-only, never transmitted.
- FIRE calculator
FIRE number, years to independence, path chart, and savings-rate sensitivity, localStorage inputs.
- Credit card payoff calculator
Minimum vs fixed payments vs payoff-by-date, balance chart and interest totals.
- Debt snowball vs avalanche visualizer
Multiple debts, extra budget, months, interest, payoff order, and chart for both strategies.
- Mortgage amortization calculator
Amortization table, PMI and escrow, prepayments, CSV export.
- Roth vs Traditional IRA comparator
Federal brackets and optional state tax, after-tax projection chart vs Traditional.
- Loan calculator
Monthly payment, total interest, and amortization from principal, rate, and term.
- Loan payoff strategy calculator
Extra principal each month, months and interest saved vs minimum payment.
- Break-even calculator
Fixed costs, variable cost per unit, and selling price to find break-even units and revenue.
- ROI calculator
Net profit and cost of investment to ROI percentage, return multiple, and optional annualized ROI.
- Airline Mile Value Calculator
Calculate the real cash value of airline miles and points across major loyalty programs.
Personal finance
Rent vs buy, take-home pay, and big personal-money decisions.
- Emergency fund calculator
Monthly essentials × coverage minus cash on hand, with a grounded month-by-month fill plan.
- Take-home pay calculator (US)
Federal, state, FICA, and pre-tax benefits, net pay per check for 2026.
- Take-home pay calculator (UK)
2025/26 Income Tax, NI, pension, and student loan, net pay with donut breakdown.
- Take-home pay calculator (Pakistan)
FY 2025-26 FBR slabs, EOBI, provident fund, salaried and freelancer modes with effective tax rate.
- Retirement withdrawal calculator (4% rule)
Trinity-style safe withdrawal, year-by-year depletion, SS offset, and multi-rate comparison.
- Pension vs lump sum calculator
Break-even age and NPV, monthly pension vs invested lump sum with COLA and return sensitivity.
- HELOC vs cash-out refinance calculator
Total interest and closing costs side-by-side, find when refi pays back its closing costs.
- Rent vs buy crossover
Find the year buying beats renting, interactive graph with your assumptions.
E-commerce
ROAS, margins, fees, and marketplace economics.
- Break-even ROAS calculator
COGS, shipping, payment fees, refunds, minimum ROAS to cover variable costs.
- Amazon FBA profit calculator
USD fees from the 2026 Q2 excerpt, referral floor, fulfillment ladder, per-unit KPIs, horizon multiply.
- Etsy profit calculator
Per-order profit after 2026-style Etsy fees, transaction on price + shipping charged, US processing, Offsite Ads toggle.
- Shopify profit calculator
Basic vs Shopify vs Advanced net at your volume, 2026 plan fees, Shopify Payments or third-party stack, apps, and CAC per order.
- LTV / CAC ratio calculator
E-commerce vs subscription LTV, CAC, payback months, health bands, and one-step churn or frequency sensitivity.
- Print-on-demand profit calculator
POD profit after fees and shipping, break-even price, stacked breakdown, Printful vs Printify vs MBA.
- AOV optimizer
Free shipping, upsell, and bundle levers, new AOV, monthly revenue lift, and gross profit by tactic.
- Inventory turnover calculator
Turnover, days on hand, holding cost, and cash freed when you hit a target turnover rate.
- Wholesale markup calculator
Cost to wholesale to retail chain, markup vs margin, keystone badges, reverse from any tier.
- Markup calculator
Calculate selling price and gross profit from cost and markup percentage. Understand markup vs margin.
Freelance & agency
Hourly rates, quotes, and consulting economics.
- Freelance hourly rate calculator
Minimum rate from take-home goals, taxes, expenses, and billable hours.
- Freelance retainer scope builder
Tier cards with effective hourly, below-rate warnings, deliverable rows, and capacity bar chart.
- Project quote calculator
Dynamic phase rows, fixed-price toggle, totals block, blended rate KPI, and copy quote for proposals.
- Hourly to annual salary converter
Three modes: hourly to annual, annual to hourly, freelance vs salaried with SE tax, benefits, and PTO value.
- Late payment interest calculator
Overdue invoice interest, simple or compound, accumulation chart, jurisdiction notes, demand copy.