Free Finance Tools & Calculators
Browse 356+ free interactive finance calculators, estimators, and utilities. 100% free, private, and runs directly in your browser without signup.
MIRR Calculator (Modified IRR): Compute Modified Internal Rate of Return
Free MIRR calculator: compute Modified Internal Rate of Return from cash flows with separate finance & reinvestment rates, compare IRR vs MIRR, rank 2 projects, and solve for the reinvestment rate.
Cashier Change Calculator — Compute Change + Rupiah Denomination Breakdown
Compute cashier change: purchase total and cash paid become change plus an optimal rupiah denomination breakdown. Includes a limited cashier-stock mode, a two-payment comparator, and a wallet solver. Free, 100% in-browser.
Money Counter: Count Total Rupiah Stack + Denomination Breakdown
Count the total value of a rupiah cash stack: enter the count of each denomination to get the total plus per-denomination breakdown. Includes a target-check mode, two-stack comparator, and denomination combinations. Free, 100% in-browser.
Money Market Account (MMA) Calculator — Tiered Interest, Break-Even & Projection
Money market account calculator: compute tiered interest rates, compare MMA vs savings vs CDs, find the break-even balance for monthly fees, and project 12 months with regular deposits.
Money Multiplier Calculator
Macroeconomics money multiplier calculator: simple model m = 1/rr, full model m = (1+c)/(rr+e+c), policy-scenario comparator, and solver. 100% runs in your browser.
Money Supply Calculator (M0/M1/M2) — Money in Circulation
Compute monetary aggregates M0, M1, and M2 from their components (currency, demand deposits, savings, time deposits), compare two periods, compute from monetary base × money multiplier, or find the component needed for an M2 target.
Month-over-Month (MoM) Calculator: Monthly Growth & Annualization
Calculate month-over-month (MoM) growth: % change vs last month, monthly series with average MoM, annualization (1+m)^12-1, target value solver, and two-series comparator. Free, 100% in your browser.
Monthly Income Calculator — Gross & After-Tax Monthly Income from Any Pay Frequency
Free monthly income calculator: combine multiple income streams (hourly, weekly, biweekly, monthly, annual), estimate after-tax monthly take-home pay, and break it into a 50/30/20 monthly budget.
Moratorium EMI Calculator — Loan Moratorium Interest Cost
Free moratorium EMI calculator: see how pausing loan EMIs accrues interest. Compare 3 post-moratorium options — tenure extension, EMI increase, or lump-sum interest payment — with full amortisation tables.
Mortgage Calculator UK — Monthly Payments, Borrowing Power, Stamp Duty & Stress Test
Free UK mortgage calculator: monthly payments in £, how much you can borrow (4.5x income + affordability), stamp duty SDLT with first-time buyer relief, lender stress test, LTV rate bands, Help to Buy & First Homes.
Mortgage Insurance Lab — PMI Calculator, FHA MIP, VA Funding Fee & USDA Fees
Free mortgage insurance lab: PMI calculator with credit-score rate estimator, PMI removal date calculator (with extra payments), upfront vs monthly PMI, lender-paid PMI vs borrower-paid PMI, piggyback 80-10-10 vs PMI, FHA MIP calculator (upfront + annual, 11-year rule), FHA vs conventional comparator, VA funding fee calculator and USDA guarantee fee calculator. 100% client-side.
Mortgage Penalty Calculator — Canada IRD + US Prepayment Penalty
Free mortgage penalty calculator: Canada IRD (interest rate differential) vs 3-month interest — compare Big-6 posted-rate vs fair monoline methods — plus US prepayment penalty types (declining, % of balance, yield maintenance) and a refinance break-even analyzer.
Mortgage Refinance Break-Even Calculator — Monthly Savings, Break-Even & Total Cost | nrtechstudio.com
Free mortgage refinance break-even calculator: monthly savings, break-even months, total interest old vs new, net savings over your horizon, and a don
Motorcycle Loan Calculator — Payment, Down Payment, Gear & Amortization
Free motorcycle loan calculator: monthly payment with down payment and trade-in, gear and accessories financing, dealer fees, sales tax, 24-84 month term comparison, extra payments, underwater tracker, ownership costs, and full amortization schedule. 100% client-side.
Moving Average Calculator (SMA, EMA, WMA) — Moving Averages & Crossover
Calculate moving averages from a data series: per-point SMA, EMA (α=2/(n+1)), and WMA, two-period golden cross / death cross detection, plus a two-series comparator. Free, 100% in your browser.
Lawn Mowing Cost Calculator — Per Visit, Monthly & Season Estimates | nrtechstudio.com
Free lawn mowing cost calculator: estimate cost per visit, per month, and per season by lawn size, frequency, and condition. DIY vs hire comparator + quote checker. Runs 100% in your browser.
Mutual Fund Calculator — SIP, Lump Sum Projections & Compare 2 Funds
Mutual fund calculator: lump sum & monthly SIP projections, compare 2 mutual funds (return & expense ratio), and solve for contribution/tenor/return from a target amount. Free, no sign-up.
UK National Insurance Calculator 2026/27 — Employee & Employer NI
UK National Insurance calculator for tax year 2026/27: calculate employee Class 1 NI (8%/2%), employer NI (15%), compare two salaries, and solve gross pay from an NI target. Free, educational estimate.
NPS Calculator – National Pension Scheme Corpus & Monthly Pension Estimator
Free National Pension Scheme calculator: project your NPS Tier 1 corpus, lump-sum withdrawal and monthly pension. Includes pension target solver, government employee mode, Tier I vs Tier II comparison, exit rules and tax benefits. Also works for NRI subscribers.
Natural Rate of Unemployment Calculator (NAIRU) — nrtechstudio.com
Natural rate of unemployment (NAIRU/NRU) calculator: compute NRU from frictional and structural components, cyclical unemployment, Okun's law output gap, two-region comparator, and solver. Free, educational, 100% in your browser.
Net Debt Calculator — Calculate Company Net Debt
Free net debt calculator: compute net debt (total interest-bearing debt − cash), component breakdown, compare 2 companies, and net debt target solver.
Net Effective Rent Calculator — Free
Net effective rent calculator: compute effective monthly rent after concessions (free rent, TI allowance), break down each concession's impact, compare 2 lease offers, and simulate a rent target. Free, 100% in your browser.
Net Force Calculator — 1D & 2D + Vector Diagram
Free net force calculator: sum 1–10 forces (magnitude + angle or Fx/Fy components), get F_net, direction, components, worked steps, and an SVG vector diagram. 1D collinear & 2D modes. N, kN, lbf units. 100% client-side.
Net Income Calculator — Calculate Company Net Income
Free net income calculator: compute company net income from revenue, COGS, operating expenses, interest & tax — plus multi-step income statement, 2-company comparator, and target profit solver.
Net Operating Assets (NOA) Calculator — Net Operating Assets
Net Operating Assets (NOA) calculator: compute net operating assets from balance-sheet components or the identity, measure RNOA, compare 2 companies, and simulate an RNOA target. 100% free in your browser.
Net Operating Income (NOI) Calculator — Property & Business NOI
Free NOI calculator: compute property net operating income (effective rental revenue − operating expenses) & business, compare 2 properties, plus target NOI solver. Runs 100% in the browser, no sign-up.
NPV Calculator — Net Present Value, IRR, Payback & Pension Valuation
Free net present value calculator: NPV of projects with variable discount rates, IRR, MIRR, profitability index, discounted payback, sensitivity analysis, cash-flow timeline chart, and pension NPV / lump-sum buyout valuation. 100% client-side.
Net Worth Calculator & Tracker — Free, No Signup | nrtechstudio
Free net worth calculator with detailed asset & debt breakdown, private local tracker with month-over-month trends, percentile-by-age benchmark, and a 5-year what-if projector. No signup — your data never leaves your browser.
New York Overtime Pay Calculator — 1.5× for Hours Over 40
Calculate New York overtime pay: 1.5× the regular rate for hours over 40/week + check your rate against the NYC $17.00, Long Island & Westchester $17.00, and rest of NY $16.00 minimum wages (verified Oct 9, 2026). Hourly mode, salary→weekly mode, comparator, FAQ. Free.
NOPAT Calculator — Net Operating Profit After Tax
NOPAT calculator (net operating profit after tax): compute NOPAT from EBIT × (1−tax rate) or from revenue−COGS−expense components, compare 2 companies, and simulate NOPAT targets. 100% free in your browser.
Normal Force Calculator — Flat, Inclined Plane & Elevator
Free normal force calculator: compute N = m·g (flat plane), N = m·g·cos θ (inclined plane), angled push/pull force, and N = m·(g+a) in an accelerating elevator. SVG force diagram, worked steps, kg/g/lb and N/kN/lbf units. 100% client-side.
Net Promoter Score (NPS) Calculator — Calculate NPS 0–10
Free Net Promoter Score (NPS) calculator: compute NPS from 0–10 survey scores, compare two periods, and simulate what's needed to reach a target NPS. 100% runs in the browser.
NSFR Calculator (Net Stable Funding Ratio)
Basel III NSFR (net stable funding ratio) calculator: compute the net stable funding ratio from ASF/RSF components, view standard factor tables, compare 2 banks, and simulate the 100% NSFR target.
Operating Cash Flow (OCF) Calculator — Calculate Operating Cash Flow
Free operating cash flow (OCF) calculator: compute operating cash flow via the indirect method from net income, working capital, margin, and OCF target solver.
Outdoor Kitchen Size Calculator — Grill Zone, Counter, Seating & Pergola
Plan your outdoor kitchen size: grill zone, counter run, sink, fridge, bar seating, pizza oven, clearances and pergola dimensions — free calculator.
Packing List Generator — Smart Travel Packing Checklist | nrtechstudio.com
Free packing list generator: build a custom travel packing checklist by trip type, days, season and destination. Item-per-day quantities, baggage weight estimate, printable checklist. 100% private, no signup.
House Painting Cost Calculator — Interior, Exterior, Cabinets, Deck | Painting Cost Lab
Estimate your house painting project cost room-by-room: interior, exterior, kitchen cabinets, deck and fence. Prep-level, regional labor and DIY-vs-pro comparison. Free, private, no signup.
Patent Cost Lab — USPTO Patent Cost Calculator (2025 Fees) | nrtechstudio.com
Free USPTO patent cost calculator: 2025 fee schedule × large/small/micro entity, provisional vs utility comparator, maintenance fees, 20-year total cost, attorney ranges, and PCT international route estimator. Educational estimates — not legal advice.
Pence to Pounds Converter & Calculator — Convert Pence to Pounds
Free pence to pounds converter and calculator. Convert pence to pounds (£ = p ÷ 100), pounds to pence, batch-convert lists, and look up old pre-decimal pence. How many pence in a pound? Exactly 100.
Percent Off Calculator — Sale Price, Stacked Discounts & Reverse Solver
Free percent off calculator: sale price, discount amount, stacked discounts (20% off + extra 10%), tax-inclusive totals, reverse original-price solver, and deal comparison. 100% private, runs in your browser.
Pest Control Cost Lab — How Much Does Pest Control Cost? Termite, Bed Bug & Exterminator Price Calculator
Free pest control cost lab: per-pest price estimates for termites, bed bugs, cockroaches, rodents, wasps & fleas; termite treatment method comparator (fumigation vs bait vs liquid barrier vs heat); per-linear-foot termite engine; quarterly-plan vs one-time total cost; DIY-vs-pro gate; 50-state pricing multipliers. 100% client-side.
Pet Sitter Rates Calculator — Fair Prices for Sitting, Boarding & Dog Walking
Free pet sitter rates calculator: estimate fair drop-in visit, dog walking, boarding & overnight sitting prices by pets, location & holidays. Sitter pricing advisor + quote checker included.
Pinewood Derby Speed Lab — CoG Solver, Weight Planner, Rail-Riding & Rules Checker
Free pinewood derby speed lab: center-of-gravity solver, 5 oz weight budget planner, rail-riding setup calculator, wheel/axle prep checklist, graphite vs Krytox lube advisor, and BSA rules checker. 100% client-side, no signup.
Pipe Volume Calculator
Pipe volume calculator: internal capacity from ID x length in gallons, litres and ft3, partial fill, multi-section system volume, reverse length and NPS schedule table.
Plant Population Calculator — Plants per Acre, Hectare & Seeding Rate | nrtechstudio.com
Free plant population calculator: plants per acre & hectare from row and in-row spacing, reverse spacing finder, seeding rate, seed-bag & field planner. Corn, soybean, wheat, cotton reference tables. 100% private — runs in your browser.
Planter Box Size Calculator — 7 Ways to Size & Build a Planter Box
Free online planter box size calculator with 7 modes: size planter boxes by plant type, compute soil volume in cubic feet, gallons and bags, plan drainage holes, generate a cedar lumber and materials list, check elevated-planter leg height and loaded weight, lay out multiple boxes on a patio, and estimate build cost. Runs 100% in the browser.
Plasma Osmolality Calculator — Calculated Posm & Osmolar Gap
Free plasma osmolality calculator: calculated Posm = 2×Na + glucose/18 + BUN/2.8 (+ ethanol/4.6), osmolar gap = measured − calculated, mg/dL ↔ mmol/L
Plasma Volume Calculator (Kaplan, Hakim) | nrtechstudio.com
Free plasma volume calculator: estimate plasma volume from total blood volume and hematocrit, or directly with the Kaplan and Hakim formulas. Ideal pl
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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.