Financial decisions, clarified
Northstar Numbers — your clearest view of financial tradeoffs
Interactive simulators and calculators built for transparency—real cash flow, scenario comparison, and ranges that respect uncertainty. Explore options and stress-test assumptions; bring your own judgment to every decision.
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Decision Simulators
Financial Future Simulator
Model how income, spending, investing, housing, and major life decisions affect your net worth over time. A full financial life-path simulator.
Try the simulator →Interactive SimulatorFIRE Probability Engine
Model your path to financial independence and early retirement. See how savings, spending, investment returns, and time horizon affect your probability of success.
Try the simulator →Interactive SimulatorFIRE Path Selector
Compare Lean FIRE, Barista FIRE, and Fat FIRE paths side by side. See which path to financial independence fits your life, what each requires, and when you can get there.
Try the simulator →Interactive SimulatorBarista FIRE Simulator
Model semi-retirement with part-time income: Barista FIRE number vs full FIRE, portfolio trajectories, bridge period, and savings rate to hit your target age.
Try the simulator →Interactive SimulatorHouse Hack Simulator
Explore how buying a property and renting out part of it can slash your housing costs and accelerate wealth building.
Try the simulator →Interactive SimulatorRent vs. Buy Simulator
Explore whether renting or buying makes more financial sense with real numbers, visual comparisons, and a clear breakeven analysis.
Try the simulator →Interactive SimulatorJob Offer Comparison Simulator
Compare two job offers side-by-side including salary, benefits, bonuses, commute, flexibility, and work-life balance to see which opportunity truly comes out ahead.
Try the simulator →Interactive SimulatorDivorce Financial Impact Simulator
Explore post-divorce finances with adjustable assumptions for housing outcomes, asset split, debt split, support payments, and long-term wealth trajectories for both households.
Try the simulator →Interactive SimulatorHealth Insurance Gap Simulator
Calculate your health insurance costs when leaving employer coverage before Medicare eligibility. See COBRA vs. ACA marketplace costs, subsidy eligibility, the 400% FPL cliff, and your year-by-year total healthcare spend.
Try the simulator →Interactive SimulatorSide Hustle to Full-Time Simulator
Model how your side hustle could grow over time and estimate when it might realistically replace your salary. Explore growth scenarios, savings runway, and your Freedom Score.
Try the simulator →Decision Calculators
- Decision Calculator
Pay Raise Impact Calculator
Understand what a raise actually changes. Estimate after-tax monthly impact, inflation-adjusted raise strength, and practical savings progress from your new compensation.
Use calculator → - Decision Calculator
Investment Growth Calculator
Project how your portfolio could grow with initial balance, recurring contributions, and expected returns. See contributions vs. gains, inflation adjustment, and a growth chart.
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Mortgage Payoff Calculator
See how extra payments accelerate your mortgage payoff and reduce total interest. Compare scheduled vs. accelerated payoff, interest saved, and your new payoff date.
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Coast FIRE Calculator
Find your Coast FIRE number—how much invested today would grow to your retirement target without additional contributions. See compound growth in action.
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Property Appreciation Calculator
Project how your home's value could grow over time. See future equity, total appreciation, and wealth from real estate. Ideal for homeowners and investors.
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Savings Rate Calculator
Calculate your savings rate and see how it affects your path to financial independence. Compare your rate to FIRE benchmarks and visualize years to FI.
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Side Hustle Impact Calculator
Estimate the real financial impact of a side hustle. See after-tax income, effective hourly earnings, and long-term wealth potential.
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Big Purchase Timing Calculator
See how buying a car, renovation, wedding, boat, or other large purchase now vs later affects your future wealth. Compare buy now, buy later, and skip scenarios with inflation, depreciation, and opportunity cost.
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Sabbatical Impact Simulator
See how taking a sabbatical, career break, or extended time off affects your savings, investments, and long-term financial trajectory. Compare no-sabbatical vs. sabbatical scenarios.
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Retail Store Profit Calculator
Estimate retail store profitability, margins, break-even revenue, and required customer traffic. Model revenue, COGS, and operating expenses for any brick-and-mortar retail business.
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Online Store Profit Calculator
Estimate ecommerce profitability by modeling product costs, shipping, platform fees, payment processing, advertising spend, and margins. Works for Shopify, Amazon, Etsy, and any online store.
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Quick Calculators
Tip Calculator
Quickly calculate restaurant tips and optionally split the bill between multiple people.
Open →Days Between Dates Calculator
Find the number of days and duration between two calendar dates.
Open →Percentage Change Calculator
Find the percent increase or percent decrease from one value to another.
Open →Percentage Calculator
Calculate what is X% of Y, what percent X is of Y, or X increased or decreased by Y%.
Open →Time Between Times Calculator
Find the duration between two times in hours and minutes, including overnight ranges.
Open →Salary to Hourly Calculator
Convert annual salary to hourly pay or hourly wages to yearly salary, with pay breakdown by period.
Open →Pay Raise Calculator
See how a raise changes your pay. Enter current pay and a percentage or flat-dollar raise for a clear before/after comparison and period breakdown.
Open →Overtime Pay Calculator
Estimate overtime pay from hourly wage, overtime hours, and multiplier (e.g. 1.5x). See overtime rate, total overtime pay, and optional total pay with regular hours.
Open →Age Calculator
Calculate age from a date of birth with an optional reference date and a detailed breakdown of elapsed time.
Open →Date Add and Subtract Calculator
Add or subtract days from a given date to quickly find the resulting calendar date.
Open →Business Days Calculator
Calculate the number of business days between two dates, excluding weekends by default.
Open →Unit Converter
Convert between common measurements including length, weight, temperature, and volume.
Open →Countdown Calculator
See how much time is left until a future date with a clear days, hours, and minutes breakdown.
Open →Ratio Calculator
Simplify ratios to lowest terms and solve for a missing value in equivalent ratios.
Open →Average Calculator
Calculate the mean of a list of numbers. Enter values separated by commas or newlines for an instant average, count, and sum.
Open →Fraction Decimal Converter
Convert between fractions and decimals in either direction. Enter a fraction (numerator and denominator) or a decimal for instant results and percentage.
Open →Loan Payment Calculator
Estimate your monthly payment from loan amount, interest rate, and term. See total paid and total interest in a clear breakdown.
Open →Compound Interest Calculator
Calculate future value with compound interest. Enter initial amount, rate, time, and compounding frequency. Optional monthly contributions and a clear growth breakdown.
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