Free Finance Tools & Calculators
Browse 356+ free interactive finance calculators, estimators, and utilities. 100% free, private, and runs directly in your browser without signup.
India HRA (House Rent Allowance) Exemption Calculator — Free Calculation
Free India HRA exemption calculator: compute the 3 Section 10(13A) components, compare metro vs non-metro cities, find minimum rent from an exemption target, and estimate taxable HRA.
HSA vs FSA Calculator — 5-Year Comparison, 2026 IRS Limits & Forfeiture Risk (Free)
Free HSA vs FSA calculator: 5-year net-value comparison with 2026 IRS limits, rollover vs forfeiture simulator, triple-tax-advantage explainer, tax-savings breakdown and a clear verdict. 100% private — runs entirely in your browser.
HVAC Repair vs Replace Calculator — $5,000 Rule, 10-Year Cost & Quote Checker | nrtechstudio.com
Free HVAC repair vs replace calculator: the $5,000 rule, age + SEER + repair-cost decision engine, 10-year total cost comparison, energy savings estimator, R-22 refrigerant factor, and contractor quote checker with 2026 US cost ranges. 100% private — runs in your browser.
Illinois Overtime Pay Calculator — 1.5× for Hours Over 40
Calculate Illinois overtime pay: 1.5× the regular rate for hours over 40/week (federal FLSA rule) + Illinois $15.00 and Chicago $16.60 minimum wage check. Hourly, salary-to-weekly, scenario comparison, FAQ modes. Free.
Immediate Annuity Calculator (SPIA) — Lifetime Monthly Income Estimate
Free single-premium immediate annuity (SPIA) calculator: estimate lifetime monthly income from a lump sum using age, sex, a mortality life table, and payout options — life-only, period certain, joint and survivor. 100% client-side.
Impermanent Loss Calculator (v2 & v3) — DeFi LP Risk
Free impermanent loss calculator for DeFi liquidity pools: Uniswap v2 50/50 pools and v3 concentrated ranges. Compare LP vs HODL value, find the fee APR needed to break even. Not financial advice.
Income Elasticity of Demand Calculator
Interactive income elasticity of demand calculator: compute Ei with midpoint or point formulas, classify luxury, necessity, and inferior goods, reverse solver, and two-good comparator.
Portfolio Information Ratio Calculator — NRTechStudio
Calculate portfolio information ratio: IR = (Rp − Rb) ÷ tracking error. From aggregate figures or a return series, with an inverse solver, a two-manager comparator, and annualization.
Interest Coverage Ratio Calculator — nrtechstudio
Calculate interest coverage ratio (ICR) from EBIT or EBITDA, reverse-solve a target ICR, and compare two companies — with substitution steps and descriptive labels. An educational estimate, not investment advice.
Interest-Only Mortgage Calculator — IO Payment, Amortization & Balloon
Free interest-only mortgage calculator: compute IO-phase monthly payment, payment after the interest-only period ends, payment shock, balloon amount, total interest, and compare vs a fully amortizing loan.
Interest Per Day Calculator — Daily Interest by Day-Count Convention
Free interest per day calculator: enter principal, annual rate, and day-count convention (Actual/365, Actual/360, 30/360) to get daily interest and period totals. Includes reverse mode to find the rate from a daily interest amount.
Implied Interest Rate Calculator — Find the Rate from Installment & Term
What percent is your loan interest really? Find the implied interest rate from principal, installment, and term with a numeric solver — plus EAR, a 2-offer comparator, and a sensitivity table. Free, 100% private in your browser.
IRR Calculator — Internal Rate of Return from Cash Flows
Free IRR calculator: compute internal rate of return from a cash flow series with a transparent bisection iteration table, NPV profile, 2-project comparison, and target IRR solver. 100% in the browser, no sign-up.
Stock Intrinsic Value Calculator (DCF) — Free Cash Flow, Terminal Value, WACC
Calculate a stock’s intrinsic value with DCF: multi-year FCF projections, Gordon/exit-multiple terminal value, WACC discount rate, down to intrinsic value per share + margin of safety, reverse DCF, scenarios, and a sensitivity table.
Inventory Turnover Calculator — nrtechstudio
Inventory turnover calculator: compute the inventory turnover ratio from COGS and beginning/ending inventory, DIO (days inventory outstanding), reverse target-turnover solver, and two-company comparator. 100% in the browser.
Investment Fees Comparison Calculator — See What Fees Really Cost
Compare investment fee scenarios side by side: initial investment + annual contributions, gross return, and up to 3 fee levels. See future value with vs without fees, fee drag in dollars and percent, and break-even alpha.
Investment Inflation Calculator — Real Return After Inflation | nrtechstudio.com
Investment inflation calculator: find your real return after inflation and project nominal vs inflation-adjusted growth. Free, instant, no signup.
IRA Calculator — Traditional vs Roth IRA Growth Projector (2026 Limits)
Free IRA calculator: project Traditional vs Roth IRA growth side by side with 2026 IRS contribution limits ($7,500 / $8,600 catch-up), RMD age 73 flag, and early-withdrawal penalty notes. 100% private, runs in your browser.
IVF Cost Lab — IVF Total Cost Estimator (7-in-1 Suite)
Free IVF total cost estimator: per-cycle cost ranges, state insurance-mandate checker (23 jurisdictions), add-on menu (ICSI, PGT, freezing), multi-cycle planner, financing comparator, clinic quote comparison, and medication estimator. 100% client-side, no signup.
Jensen's Alpha Calculator — Portfolio α vs CAPM
Calculate portfolio Jensen's alpha: α = Rp − [Rf + β(Rm − Rf)], CAPM expected return, 4-way reverse solver, and two-manager comparator. With substitution steps and descriptive interpretation.
Jumbo Loan Calculator — Classification, Payment & Comparator (FHFA 2026 Limits)
Free jumbo loan calculator: check jumbo vs conforming classification against FHFA 2026 limits ($832,750 baseline, $1,249,125 high-cost), compute monthly payments, compare jumbo vs conforming costs, and check the DTI ratio. 100% in-browser.
LFPR Calculator — Labor Force Participation Rate
Calculate the labor force participation rate (LFPR): labor-force ÷ working-age-population × 100% formula, employed/unemployed breakdown, two-period comparator, and target solver. Free, 100% client-side.
Land Loan Payment Calculator — Land & Lot Loan Payments
Free land loan payment calculator: estimate monthly payments, total interest and balloon balance for raw land and improved lot loans. Land loans need 20-50% down, carry higher rates and shorter terms (5-20 years) than mortgages.
Laser Linewidth Converter & Calculator — Δλ ↔ Δν, Coherence Length, Q Factor
Free laser linewidth converter & calculator: convert spectral linewidth between wavelength (nm), frequency (GHz), wavenumber (cm⁻¹) and photon energy (eV). Get coherence length, coherence time and Q factor instantly.
Layaway Plan Calculator — Interest-Free Installments to the Store
Calculate a layaway plan: installments per period, payoff date, installment-target solver, compare 2 store plans, and effective-price estimate including fees & penalties. No interest.
Lerner Index Calculator — Measure Company Market Power
Lerner Index calculator: compute L=(P−MC)/P from price & marginal cost, from demand elasticity, compare 2 companies, + price/cost target solver.
Lighting Energy Cost Calculator — LED vs Incandescent, CFL & Halogen Cost Comparison | nrtechstudio.com
Free lighting energy cost calculator: find how much it costs to run a light bulb per hour, month, and year. Compare LED vs incandescent vs CFL vs halogen at equal brightness (lumens), get LED payback period, whole-home lighting cost, tiered tariff billing, and CO2 emissions.
LLC Cost by State 2026 — Filing Fees, Annual Fees & 5-Year TCO Calculator | LLC Cost Lab
How much does an LLC cost? Compare LLC filing fees and annual fees for all 50 states + DC, calculate 1/5/10-year total cost of ownership, rank the cheapest states, avoid the Delaware/Wyoming foreign-qualification trap, and estimate NY publication costs. Free, 100% client-side.
Loan Comparison Calculator — Compare Loans Side by Side
Free loan comparison calculator: compare up to 4 loan offers side by side — monthly payment, total interest, total cost, effective APR with fees, points break-even, and true cost if you exit early. 100% private, runs in your browser.
Long-Term Care Insurance Calculator & Care Cost Estimator — nrtechstudio
Estimate US long-term care (LTC) insurance premiums, nursing home, assisted living, and home care costs, compare two policy scenarios, plus a daily-benefit solver. Educational estimates.
Lottery Annuity Calculator — Lump Sum vs Annuity (Powerball & Mega Millions)
Lottery payout calculator: compare lump sum vs 30-year annuity with real 2026 federal tax brackets, state taxes, present value, and a break-even discount-rate solver. Powerball & Mega Millions presets.
LTV (Loan-to-Value) Calculator — Compute Loan-to-Property-Value Ratio
Free LTV calculator: compute loan-to-value ratio from loan and property value, two-way loan/down-payment solver, 2-scenario DP comparator, and a running-LTV tracker toward 80%. 100% client-side.
Luhn Algorithm Validator
Free Luhn algorithm (mod 10) validator with digit-by-digit steps, card type detection, check digit generator, and batch mode. 100% client-side.
Lumpsum Plus SIP Calculator — One-Time + Monthly Investment Growth
Free lumpsum plus SIP calculator (India): combine a one-time investment with monthly SIP, annual step-up, inflation-adjusted corpus, scenario comparison and year-by-year growth. Also works as a lump sum and SIP calculator / SIP with initial investment calculator.
Lumpsum Calculator — One-Time Investment Growth Projector
Free lumpsum calculator: project the future value of a one-time investment with scenario comparison (8/12/15%), year-by-year growth table, inflation-adjusted real value, INR + USD dual currency, and goal solvers. 100% client-side.
MAGI Calculator 2026 — Modified Adjusted Gross Income Calculator
Free MAGI calculator for 2026: compute Modified Adjusted Gross Income (MAGI) from AGI with IRS add-backs, and check Roth IRA, Traditional IRA, student loan interest, and education credit eligibility.
Man-Hours Calculator: Project Work Hour Estimation — nrtechstudio
Free man-hours calculator: compute total project man-hours from workers × hours/day × days, with team & duration solver, compare 2 staffing plans, and labor cost estimation. 100% in the browser.
Margin & VAT Calculator — True Margin from Tax-Inclusive Price
Free margin with VAT calculator: compute the true margin from an inc-VAT price, extract the tax first, compare ex-VAT vs inc-VAT, and a selling-price solver from a target margin.
Profit Margin Calculator: Net, Operating & EBITDA Margin | NR Tech Studio
Free profit margin calculator: net, operating, EBITDA margin, markup to margin converter, commission impact, break-even units and reference tables.
Stock Margin Call Calculator: Status, Trigger Price & Solver
Compute stock broker margin calls: account status, shortfall amount, the stock price that triggers a margin call, a 2-scenario comparator, and a deposit or sell solver. Educational estimate, not investment advice.
Discount Impact on Margin Calculator — Free
Compute the impact of discounts on profit margin: margin after discount, maximum discount to hit a target margin, a two-level discount comparator, and a list-price solver. Free, 100% in the browser.
Stock Broker Margin Interest Calculator — Margin Loan Cost
Free margin interest calculator: compute stock broker margin loan interest cost (balance × rate × days/360), a 2-broker comparator, monthly & yearly cost projection, and a maximum loan solver.
Marginal Cost Calculator — MC = ΔTC/ΔQ + Table & Solver
Marginal cost calculator: compute MC = ΔTC/ΔQ from two cost points, multi-point table analysis, compare MC vs ATC/AVC, + TC2 & Q2 solver. 100% in the browser.
Marginal Revenue Calculator — MR = ΔTR/ΔQ + Table & Solver
Marginal revenue (MR) calculator: compute MR = ΔTR/ΔQ from two points, multi-point table, MR vs MC comparator, + TR2 & Q2 solver. 100% in the browser.
Market Capitalization Calculator (Market Cap) — Price × Shares Outstanding
Compute market capitalization from share price × shares outstanding, with size classification (mega/large/mid/small/micro), fully diluted mode, a 2-company comparator, and a share price solver.
Markup Calculator — Markup to Margin Converter, Pricing & SKU Batch Tool
Free markup calculator: price from cost and markup, cost from price, two-way markup to margin converter, conversion table, discount-proof pricing and batch SKU pricelist. 100% client-side.
Meal Prep Planner — Weekly Meals, Grocery List, Cost & Macros | nrtechstudio.com
Free meal prep planner: enter people, days and calorie targets to get your weekly meal count, auto-generated grocery list with quantities, cost estimate vs budget, daily macros and prep-time plan. 100% in your browser, no signup.
Mileage Reimbursement Calculator — IRS Rates 2026, 2025, 2024 (Free)
Free mileage reimbursement calculator with official IRS standard mileage rates for 2026 (72.5¢/mi), 2025 (70¢/mi), 2024 (67¢/mi). Business mileage calculator, year-over-year rate comparison, mileage log with CSV export, and standard mileage vs actual expense comparison. 100% client-side, no sign-up.
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How to Use the Tools Directory
Every tool is a single interactive page: enter your inputs, get instant results, no account needed. Use the search box (shortcut: press /) to jump straight to a tool, or browse categories when you are exploring. Each card links to the tool's permanent URL, which you can bookmark or share.
Because all computation happens in your browser, the tools are fast, private, and free forever. If a result looks wrong, use the one-click report control on the tool page so it can be fixed.
Tool Categories at a Glance
| Category | What you will find | Example tasks |
|---|---|---|
| Developer | Encoders, formatters, regex, network tools | Format JSON, test regex, subnet a network |
| Finance | Tax, loans, salary, investing | Estimate tax brackets, amortize a loan |
| Home improvement | Estimators, measurements, materials | Size a wire, estimate paint or flooring |
| Health & fitness | Body metrics, nutrition, workouts | Track BMI, plan calories, score fitness tests |
| Math & science | Converters, geometry, statistics | Convert units, solve triangles |
| Text | Counters, sorters, generators | Count words, alphabetize a list |
| Color | Pickers, converters, checkers | Convert HEX to RGB, check contrast |
| Everyday life | Cooking, travel, automotive, pets | Convert recipes, plan fuel costs |
Popular Tasks and Where to Start
| I want to... | Start with | Why |
|---|---|---|
| Convert between number bases | Binary Converter | Step-by-step base conversion with charts |
| Validate and format data | JSON Formatter | Pretty-print and check JSON instantly |
| Count words for an essay | Word Counter | Words, characters, reading time |
| Check password strength | Password Strength Meter | Entropy-based strength scoring |
| Grade text readability | Readability Score | Flesch-Kincaid and grade levels |
| Audit color contrast | Accessibility Checker | WCAG contrast ratios in one click |
Tools Directory FAQ
What is the NRTechStudio tools directory?
It is a free catalog of more than 2,700 interactive web tools: calculators, converters, generators, and checkers for developers, finance, home improvement, health, education, and everyday tasks.
Are all the tools really free?
Yes. Every tool in the directory is free to use with no sign-up, no trial, and no paywall. They run entirely in your browser.
Do I need to create an account?
No. There are no accounts, logins, or subscriptions. Open a tool and use it immediately.
Is my data private when I use these tools?
Yes. The tools are 100% client-side: your inputs are processed by JavaScript in your own browser and never sent to a server.
How do I find the right tool?
Use the search box at the top of the directory (press / to focus it), or browse by category. Every tool card shows a short description of what it computes.
Do the tools work on mobile?
Yes. The directory and the tools use responsive layouts that adapt to phones, tablets, and desktops.
How many tools are there?
The directory holds more than 2,700 tools and grows regularly as new calculators and converters are published.
Can I request a new tool?
Yes. Each tool page has a report/feedback control you can use to request features or new tools; requests help prioritize what gets built next.
Are the tools accurate?
Calculators use published formulas and reference data (tax tables, NEC ampacity, standard conversions). Each tool page documents its method, and issues can be reported in one click for a fix.
Do tools work offline?
Once a tool page has loaded, most tools keep working without a connection because the logic is client-side JavaScript. The directory search needs the page loaded first.
What categories are covered?
Developer utilities, finance and tax, home improvement, health and fitness, math and science, text tools, color tools, networking, education, and everyday life calculators, among others.
Can I bookmark or share a tool?
Yes. Every tool has its own permanent URL under nrtechstudio.com/tools/, which you can bookmark or share directly.
Is there an API for these tools?
The tools are interactive web pages, not API endpoints. The underlying math is plain JavaScript you can inspect in the page source.
Why do some tools show ratings?
Ratings aggregate user feedback to surface the most trusted tools and flag pages that need fixes or better explanations.
How often are new tools added?
New tools are published on a continuous pipeline, prioritized by measured search demand and by user requests from the feedback controls.
Who builds these tools?
NRTechStudio, an independent tools studio focused on free, private, client-side utilities that respect user privacy.