Free Finance Tools & Calculators
Browse 356+ free interactive finance calculators, estimators, and utilities. 100% free, private, and runs directly in your browser without signup.
Pool House Size Calculator — 7 Free Planning Tools | nrtechstudio
Free pool house size calculator: 7 tools to size by swimmers, amenities, pool area, budget and setbacks, with build-cost estimates.
Post-Judgment Interest Calculator — Daily Accrual, Payments & State Rates | nrtechstudio.com
Post-judgment interest calculator: principal, statutory rate, and days. Supports partial payments, daily accrual, compounding, and per-state rate presets.
Standalone - Post Office Monthly Income Scheme Calculator
POMIS calculator — monthly payout at the official 7.4% p.a. rate
Power Unit Converter — Watts, HP, kW, BTU/h, dBm | nrtechstudio
Free power unit converter: watts, mW, kW, MW, GW, mechanical/metric/electric horsepower, BTU/h, tons of refrigeration, dBm/dBW. Plus horsepower guide, appliance wattage database with cost calculator, and generator/solar sizer. 100% client-side.
PPM to PPT Converter — ppm, ppb, ppt, ppq & Percent Converter | nrtechstudio.com
Free ppm to ppt converter: convert parts per million, billion, trillion, quadrillion and percent with show-your-work steps. Includes mg/L water mode, scientific notation and a full scale reference. 100% private — runs in your browser.
Price Per Weight Calculator — $/Lb, $/Oz, $/Kg, Compare
Free price per weight calculator: $/lb, $/oz, $/kg, $/g unit prices,
Property Tax Lab — Property Tax Calculator by Mill Rate, State, Homestead Exemption & Land Transfer Tax
Free property tax calculator lab: mill-rate math, 50-state effective-rate database, homestead exemption estimator (FL $50k, TX $140k), property tax cap projector (CA Prop 13), Ontario & Toronto land transfer tax, and Australian stamp duty (NSW/VIC/QLD). 100% client-side.
Prorated Rent Calculator — Move-In & Move-Out Partial-Month Rent
Free prorated rent calculator: actual-days vs 30-day daily rates,
Prorated Salary Calculator — Mid-Month Hire, Termination & Raise
Free prorated salary calculator: mid-month hire/termination/raise,
Standalone - Pump Horsepower Calculator
Pump horsepower calculator: water HP and brake HP from GPM and total dynamic head, NEMA motor sizing, wire-to-water effi
Raise Lab — Pay Raise Calculator: Raise % to New Pay, Reverse, Multi-Year, After-Tax, Real vs Nominal (Free)
Free pay raise calculator suite: raise % to new pay (hourly/weekly/biweekly/monthly/annual), reverse raise %, multi-year compounding projection, after-tax net raise, real vs nominal raise with inflation, pro-rata & retroactive pay, and India salary-hike CTC to in-hand. 100% client-side, no signup.
Real Estate Commission Calculator — Splits & Net Proceeds
Free real estate commission calculator: total commission,
Recipe Cost Calculator — Ingredient Cost, Per Serving & Food Cost % | nrtechstudio.com
Free recipe cost calculator: price every ingredient from its package size, get total recipe cost, cost per serving and per unit, food cost %, and a suggested selling price with your target margin. Includes a recipe scaler and kitchen unit converter. 100% client-side, no signup.
Recipe Nutrition Calculator — Calories & Macros Per Serving
Free recipe nutrition calculator: enter ingredients to get per-serving calories, protein, carbs, fat, fiber, sugar, sodium, macro split & % Daily Values. 228-ingredient USDA-based database. 100% private, no signup.
UK Statutory Redundancy Pay Calculator (2026 Rates)
UK statutory redundancy pay calculator: estimate your 2026 entitlement with age-banded weeks and the capped weekly rate (£751 GB / £783 NI).
Rent Split Calculator — Split Rent Fairly by Sq Ft, Points or Income
Free rent split calculator: split rent with roommates equally, by square footage, by room points, or based on income — with couples adjustment, utilities and surcharges. 100% client-side.
Rental Property Depreciation Calculator - MACRS 27.5 & 39 Year
Free rental property depreciation calculator: MACRS 27.5-year residential and 39-year commercial schedules with the mid-month convention, depreciation recapture estimator and cost segregation guide. 100% client-side.
Retirement Withdrawal Calculator - 4% Rule, Guardrails & Bucket Strategy
Model retirement withdrawal strategies: Bengen 4% rule, Guyton-Klinger guardrails,
RMD Calculator - Required Minimum Distribution
Free RMD calculator using the IRS Uniform Lifetime Table (2022+): single-year RMD, full table lookup, multi-year projection. 100%% client-side.
Rock Tumbling Stage Planner + Grit Calculator (Free) | nrtechstudio
Free rock tumbling lab: 4-stage planner (60/90 to polish), grit calculator by barrel size, Mohs hardness matcher, barrel fill guide, timeline estimator and shiny-rock troubleshooting. 100% private, works offline.
Rolling Offset Calculator — Pipe, EMT Conduit & Bend Marks | nrtechstudio.com
Free rolling offset calculator for plumbers and electricians: 3D pipe rolling offset, travel length, 45-degree shortcut, EMT conduit bend marks, shrink, and fitting takeoffs. 100% in-browser.
Roof Replacement Cost Calculator & Cost Lab 2026 — Estimate by Material, Pitch & Region
Free roof replacement cost calculator: convert footprint to roof squares via pitch factor, compare 9 roofing materials, tear-off layers, regional labor rates, repair-vs-replace check, insurance deductible math and financing payments. 100% client-side estimates.
Salary Calculator — Salary to Hourly Pay, Overtime & True Hourly Rate
Free salary to hourly calculator: convert annual salary to hourly wage and back, overtime pay at 1.5x time-and-a-half, your true hourly rate with unpaid overtime and commute, freelance hourly rates, and paycheck estimates. 100% private — runs in your browser.
Schengen Visa 90/180 Calculator — Track Your Days & Avoid Overstay
Free Schengen 90/180 rule calculator: log your trips, see days used in the rolling 180-day window, check planned trips, find your max stay date and next safe re-entry. 100% private — runs in your browser.
Sell-Through Rate Calculator — Unit Terjual vs Received, Multi-SKU & Reorder Planner
Free sell-through rate calculator: % units sold vs received, multi-SKU comparison with slow-mover flags, retail benchmarks & reorder planner.
Selling Leave Days Calculator - Military Leave Sell-Back Payout
Free military leave sell-back calculator: estimate your payout from unused leave days, track the 60-day career limit, and compare selling vs taking leave.
Severance Pay Calculator — Estimate Your Package, Taxes & Take-Home Pay
Free severance pay calculator: estimate your severance package from salary and years of service, add unused PTO payout by state law, see the 22% federal withholding estimate and your net take-home pay. Lump-sum vs salary-continuation comparison included.
Shed Size Calculator — Equipment Sizer, Doors, Foundation & Permits
What size shed do you need? Free 7-mode calculator: equipment sizer, stock sizes, door & walkway clearance, foundation, permits and costs.
Siding Replacement Cost Lab — Estimate Your Project + 30-Year True Cost
Free siding cost calculator: enter your home
Silver Melt Value Calculator — Sterling, Coin & Fine Silver
Free silver melt value calculator: scrap silver by weight and purity
Simple Interest Calculator — Interest on Loans, Solver & Comparison
Free simple interest calculator: interest and total with I = P x r x t, time in days/months/years, reverse solver, monthly accrual schedule and simple-vs-compound comparison. 100% client-side.
Sleep Debt Calculator: Track & Repay Your Cumulative Sleep Deficit
Free sleep debt calculator: log your nightly sleep, see your cumulative deficit vs your personal sleep need, chart 14 days, and get an honest payoff p
Small Claims Court Worth It Calculator — Expected Value by State (2026) | nrtechstudio.com
Is small claims court worth it for your claim? Free calculator: expected value from claim amount, win odds, state filing fees (all 50 states + DC), time cost, and collection risk. Plus demand letter generator. Educational estimates, not legal advice.
Sod Calculator — How Much Sod Do I Need? Rolls, Pallets & Cost | nrtechstudio.com
Free sod calculator: enter your yard dimensions to get square feet, sod rolls and pallets needed (with waste factor), plus cost estimates. L-shape, circle, polygon and sod vs seed comparison included. 100% private — runs in your browser.
Speaker Placement Calculator — 5.1, 7.1 & Dolby Atmos Layout Planner (Free)
Where should your speakers go? 5.1, 7.1 & Atmos placement angles, distances and room-fit check — free home theater layout calculator.
Startup Runway Calculator — How Long Will Your Cash Last? (Free, with Hiring & Revenue Scenarios)
Free startup runway calculator: enter cash, burn, hires and revenue growth to get your exact zero-cash date, fundraising deadline and best/base/worst scenarios. Month-by-month simulation, 100% private in your browser.
Startup Valuation Calculator — Pre/Post-Money, SAFE Note, Cap Table Dilution
Free startup valuation calculator: pre-money vs post-money valuation, SAFE note calculator (valuation cap, discount, MFN), multi-round cap table with dilution, and option pool shuffle. 100% private — runs in your browser.
Student Loan Calculator — Payment, Payoff, IDR, PSLF & Refinance Estimator
Free student loan calculator: estimate monthly payments, payoff date with extra payments, income-driven repayment (IBR, PAYE, RAP), PSLF timeline, federal vs private comparison, and refinance break-even — with year-by-year amortization and CSV export.
SUVAT Calculator
Free SUVAT calculator: solve the 5 equations of motion for s, u, v, a or t. Enter any 3 known values, get the missing one with full working shown. Sup
Swing Set Size Calculator — Yard Fit, Fall Zone & Mulch Planner
Free swing set size calculator with 7 modes: yard fit, 6-ft safety clearance, fall zone, mulch volume and budget sizing. Plan the right playset.
Take-Home Pay Calculator (2026) — Net Paycheck After Federal, State & FICA Taxes
Free 2026 take-home pay calculator: enter salary or hourly wage and see your net paycheck after federal income tax, FICA (Social Security + Medicare), state tax (CA, NY, TX, FL, custom), 401(k), HSA and deductions — with a full gross-to-net breakdown.
India TDS Interest Calculator — Late Deduction & Late Deposit (Section 201(1A))
Calculate India TDS interest: 1%/month for late deduction, 1.5%/month for late deposit
Thermal Stress Calculator: Constrained Bar Solver and Bimetallic Strip Curvature | nrtechstudio.com
Free thermal stress calculator: solve sigma = E*alpha*dT for a fully constrained bar in 4 directions, compute Timoshenko bimetallic strip curvature an
Tip Calculator & Bill Splitter — Tip with Tax, Split by Item, Etiquette Guide (Free)
Free tip calculator with tax & discount, pre-tax/post-tax tip toggle, and a bill splitter with equal, by-item and custom-share modes, per-person rounding, 20 currencies and tipping etiquette by country. 100% in-browser, no signup.
Trademark Cost Calculator 2026 — USPTO Fees, 45-Class Finder & 10-Year TCO | Trademark Cost Lab
How much does a trademark cost? Free interactive lab: 45-class Nice finder, current USPTO fee schedule ($350/class, 2025), 10-year TCO calculator, multi-country estimator (US/EU/UK/CA/AU/IN), attorney vs DIY comparison, trademark vs LLC guide, and renewal deadline planner. 100% client-side.
Traffic Ticket Cost Calculator by State 2026 — True Cost, Insurance & Points | Traffic Ticket Cost Lab
How much does a traffic ticket really cost? Free 50-state calculator: speeding fines + court costs, 3-5 year insurance increase, points by state, traffic-school dismissal math, fight-vs-pay attorney expected value, CDL penalties, and red-light camera vs officer ticket comparison. Educational estimates — not legal advice.
Trip Budget Planner — Per-Category Travel Budget Calculator
Free trip budget planner: per-category travel budget (flights, hotels, food, activities, transport, insurance), per-day auto-split, multi-destination mode, per-person view, 10% emergency buffer, 14 currencies and an actual-vs-budget tracker. 100% client-side, no signup.
UK Take-Home Pay Calculator 2026/27
UK take-home pay calculator for 2026/27 — gross salary to net pay after Income Tax (20/40/45%) and National Insurance (8/2%), reverse solver, comparison and marginal-rate breakdown. 100% client-side.
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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.