Free Online Tools for Everything You Do
Browse 2,706+ free interactive tools - home improvement estimators, pet calculators, cooking converters, automotive tools, finance planners, fitness calculators, developer utilities and more. No sign-up. 100% private. Runs entirely in your browser.
Fuel Injector Flow Rate Calculator — Sizing, Pressure Correction & cc/min to lb/hr
Size fuel injectors from target HP and BSFC, correct flow for fuel pressure with the sqrt law, and convert cc/min to lb/hr. BSFC presets labeled by source.
Fuel Mileage Calculator — Real-World MPG & L/100km from Fill-Up Data
Calculate your car's real fuel mileage from fill-up data: distance driven + fuel used = MPG (US/UK), L/100km, km/L. Multi-tank log with honest partial-fill handling, plus fuel cost per km.
Fuel Mix Calculator — 2 Stroke Oil Ratio, Premix Chart & Cost | nrtechstudio.com
Free 2-stroke fuel mix calculator: exact oil per litre or gallon for 50:1, 40:1, 32:1 and more. Brand presets, reverse solver, batch cans, cost per tank.
Fuel Savings Calculator — Compare Cars, Habits & Trip Cost | nrtechstudio.com
Compare two cars' fuel cost: MPG and gas price in, yearly gallons and dollars saved, plus upgrade payback, driving habit savings, and trip fuel cost. Free.
Funny Text Generator – Glitch, Creepy & Cursed Text
Online funny text generator with glitchy text, creepy font generator, distorted text, alien text, corrupt text, hacked text, and animated glitch text effects.
Furnace Size Calculator (BTU) — Heating Load, AFUE Correction & Standard Sizes
Free furnace size calculator: estimate heating BTU from square footage, climate zone and insulation, correct for AFUE, and find the right size.
Future Salary Calculator — Project Salary Growth & Inflation Impact
Free future salary calculator: project your salary with annual raises over N years, compare conservative / expected / optimistic scenarios, adjust for inflation, and see lifetime earnings. 100% private, runs in your browser.
Future Value Calculator — Lump Sum + Monthly Contributions
Free future value calculator: grow a lump sum plus monthly, quarterly or annual contributions at any compounding frequency. See future value, total contributions, interest earned, inflation-adjusted value, year-by-year table and chart.
Uneven Cash Flows Future Value Calculator (FV & PV) — nrtechstudio
Compute future value (FV) and present value (PV) of an uneven per-period cash flow series, with a per-cash-flow contribution table and a two-scenario comparator. Free, 100% in the browser.
Future Value Factor Table (FVIF & FVIFA) — nrtechstudio
Interactive future value factor table: look up FVIF(r,n) = (1+r)^n and FVIFA(r,n), full 1–20% × 1–30 period table, click cells for details, download CSV, plus FAQ.
Futures Contract Calculator: Notional Value, Margin, P&L & Tick
Free futures contract calculator: calculate notional value, initial & maintenance margin, leverage, long/short P&L after commissions, and P&L per tick.
G CC to LB FT3 – Density Converter & Mass-Volume Calculator
G cc to lb ft3, g to cm3, lb ft 3 to kg m 3, g cc to kg m 3, g ml to lb in3, kg to cm3, convert g cc to lb ft3, kg per m3, kgs to m3, how to convert g cm3 to lb in3, lbm to ft3, kg m to g cm, 1 g cm 3 to kg m 3, convert gm cm3 to lb in3, convert cm3 to g, m 3 kg to ft3 lb, cm3 to grams calculator, density kg m3, convert meter to kg, lbs gal to kg m3, gr cm3 ke kg m3, how to convert density to grams.
GAA Calculator — Goals Against Average & Save Percentage (Goalie Stats)
Free goals against average (GAA) calculator for goalies in soccer, ice hockey, lacrosse and field hockey. Plus a save percentage calculator. 100% client-side.
Gabapentin Dosage Calculator — Titration Schedule, Renal Dosing & Dog/Cat Dosing | nrtechstudio.com
Free gabapentin dosage reference: FDA-label human titration schedule (Day 1 300 mg to 1800 mg/day), creatinine-clearance renal dose adjustment, and ve
GAD-7 Anxiety Test & Scoring Calculator | Free Online
Free GAD-7 generalized anxiety disorder test: answer 7 questions, get your score (0-21), severity band, and what to do next. Screening tool, not a dia
Capital Gains Tax Calculator & Regional Tax Suite
Interactive capital gains tax calculator, stock investment income calculator, Virginia sales tax calculator, and Georgia business tax estimator.
Gallon to Tons Converter | Gallons to Tons Weight Calculator
Free gallon to tons calculator. Convert US and imperial gallons to metric tons, kilograms, US tons, long tons and pounds using liquid density (water, diesel, gasoline, oil, milk) or a custom kg/L value. Works both ways: tons to gallons too.
Gallon Converter: US and Imperial Gallons to Liters, Quarts, Pints, Cups, Ounces
Free gallon converter: convert gallons to liters, quarts, pints, cups and fluid ounces in US and imperial units. 1 US gallon = 3.78541178 liters, 1 imperial gallon = 4.54609 liters. Formula, quick table, and FAQ.
Gallons per Minute (GPM) Calculator
Gallons per minute calculator: bucket fill-time test, GPM converter (L/min, m3/h, GPH, CFS, L/s), fill-time planner, well drawdown and fixture tables.
Game Room Size Calculator — Room Dimensions for Pool, Ping Pong, Arcade & More
Free game room size calculator: room dimensions for pool tables, ping pong, foosball, arcade cabinets, TV viewing distance, seating, and home bars.
Garage Size Calculator — Single, Double & 3-Car Garage Planner
Free garage size calculator with 7 modes: single and double garage sizers, vehicle fit check, door size, 3-car planner, storage layout and unit conver
Garage Workshop Size Calculator — Workbench & Station Layout Planner
Free garage workshop size calculator with 7 planners: workbench walls, machine stations, 42-inch aisles, storage, power and lighting.
Garden Room Size Calculator — What Size Garden Office, Gym or Studio Do I Need?
Free garden room size calculator: size your garden office, gym, studio, lounge or guest room — with UK planning rules and US permit guidance.
Garden Soil Volume Calculator - Raised Bed, Topsoil, Mulch, Potting Mix
Free garden soil calculator: cubic feet, cubic yards, litres, tonnes & bag counts for raised beds, round beds and custom volumes. 5 materials, soil-mix recipes (Mel's Mix, 60/30/10, hugelkultur) and bulk-vs-bag cost comparison.
Gas Density Calculator (ρ = PM/RT) — Any Gas via Molar Mass
Calculate the density of any gas from pressure, temperature, and molar mass with ρ = P·M/(R·T). Presets O₂, N₂, CO₂, He, H₂, CH₄, dry air + custom molar mass. Output kg/m³, g/L, lb/ft³ + comparison vs air.
Gastric Sleeve Weight Loss Calculator — %EWL, Monthly Projection & BMI Milestones
Gastric sleeve weight loss calculator: enter starting weight and height to see your %EWL, a month-by-month gastric sleeve weight loss projection with a typical p25–p75 range, BMI trajectory and milestones. Educational only — not medical advice.
Gauss’s Law Calculator — Electric Flux & Field
Electrostatics Gauss’s law calculator: compute electric flux Φ=Q/ε₀, point-charge field E=kQ/r², infinite wire E=λ/(2πε₀r), and infinite plane E=σ/(2ε₀). Two-way solver + field direction explanation.
Gay-Lussac's Law Calculator - P₁/T₁ = P₂/T₂ Solver (Free)
Free Gay-Lussac's law calculator: solve P₁/T₁ = P₂/T₂ for any missing variable. Pressure in Pa, kPa, bar, psi, atm or mmHg; temperature in °C, °F or K (auto-converted to kelvin). Instant results with
Gazebo Size Calculator — Capacity, Guests, Furniture & Space Planner
Find the right gazebo size for your event: guest capacity, furniture fit, hot tub sizing, roof clearance and patio fit. Free 7-in-1 calculator.
Gcd Lcm
Calculate GCD / GCF and LCM with step-by-step solutions.
GCF of Monomials Calculator
High-performance factoring calculator, greatest common factor of monomials and polynomials solver with step-by-step factorization.
Glasgow Coma Scale (GCS) Calculator — E/V/M Scoring, Severity Bands & Paediatric Variant | nrtechstudio
Free Glasgow Coma Scale calculator (Teasdale & Jennett 1974): interactive E1–4 / V1–5 / M1–6 scorer with total 3–15, mild/moderate/severe bands, i
GDP Calculator — Nominal GDP, Deflator, Gap, Growth, Per Capita
One-stop GDP calculator: compute nominal GDP from C+I+G+NX components, GDP deflator, GDP gap, GDP growth, and GDP per capita. Free, educational.
GDU Calculator – Growing Degree Units (GDD) for Crops
Free GDU / growing degree days calculator for corn, soybean, wheat, alfalfa, sorghum and cotton. Accumulate daily heat units, track growth stages (emergence, V6, tasseling, silking, black layer) and f
Gear Ratio Calculator — Ring & Pinion, Final Drive & Effective Ratio | nrtechstudio.com
Free gear ratio calculator: ring & pinion ratio from tooth counts, combined transmission × transfer case × axle ratio, compound gear trains, and effective ratio after a tire-size change. Includes a standard axle-ratio chart and FAQs.
Gear Ratio RPM Calculator — Engine RPM from Speed, Gears & Tire Size | nrtechstudio.com
Free gear ratio RPM calculator: find your engine RPM at any speed from your gear ratio and tire size. RPM = (MPH × ratio × 336.13) ÷ tire diameter. Includes RPM-vs-speed table, overdrive support, metric tire sizes, and a re-gear planner for bigger tires.
Gear Ratio Speed Calculator — Speed from RPM, Gear Ratio & Tire Size | nrtechstudio.com
Free gear ratio speed calculator: find vehicle speed in mph and km/h from engine RPM, transmission + axle gear ratio, and tire size. Includes per-gear speed table, top-speed-per-gear estimator, metric tire input (e.g. 265/70R17), formula 336.13 explained, and worked examples.
Gematria Calculator: Hebrew, Jewish and English Gematria Values
Free gematria calculator: compute Hebrew (Mispar Hechrechi), Jewish, English, Simple/Ordinal and Reduced gematria values for any word or name. Side-by-side comparison, letter-by-letter breakdown and reference tables.
Secret Key & Cryptographic Multi-Hash Generator
High-entropy secret key generator, AES encryption key generator, multi hash generator (SHA-256, SHA-1, SHA-512), random token builder, and hash identifier.
How Many Generations Ago Was That? — Generation Calculator
Free generation calculator: convert any year into generations ago with adjustable generation length (25/30/custom). Famous-event presets, ancestor count (2^n), ancestor age at any event, and a visual generation timeline. 100% private — runs in your browser.
Random Codes, Name Wheel & Number Generator
High-performance generator random codes, interactive random name wheel, name raffle, and cryptographic number generator.
Generator Wattage Calculator — What Size Generator Do I Need?
Generator wattage calculator: enter your appliances' running and starting watts to find the right generator size — honest surge math, headroom guidance, fuel runtime estimator and safety guide.
Georgia Overtime Pay Calculator — 1.5× for Hours Over 40
Calculate Georgia overtime pay: 1.5× your regular rate for hours over 40/week. Hourly & salary modes, $684 exempt-threshold check, effective hourly rate. Free.
Georgia Sales Tax Calculator – Multi-State & Local Tax
Georgia sales tax calculator, new york sales tax calculator, ny sales tax calculator, texas state tax calculator, ny state sales tax calculator, california state sales tax calculator, new jersey sales tax calculator, new york city sales tax calculator, how to find tax percentage, how to find sales tax rate, sales tax calculation formula, sales tax calculator app, tax commission calculator.
Geriatric BMI Calculator (65+) — Senior BMI Cutoffs, Chart & Healthy Range
Free geriatric BMI calculator for adults 65+. Uses senior-specific cutoffs verified against ESPEN/GLIM guidelines: underweight below 23, normal 23–30, overweight 30+. Compare vs standard adult BMI, see your healthy weight range, and learn about sarcopenia and the obesity paradox.
Gestation Calculator — Animal Due Date & Pregnancy Countdown | nrtechstudio.com
Free multi-species animal gestation calculator: pick a species and enter the breeding date to get the due-date window and pregnancy countdown for dogs
Gestational Age Calculator — How Many Weeks Pregnant Am I?
Free gestational age calculator: enter your LMP, conception date, ultrasound CRL, or IVF transfer date to get your current gestational age in weeks and days, estimated due date, trimester, countdown, and a visual 40-week timeline. 100% client-side.
Free GIF to JPG Converter — No Upload, 100% in Browser
Convert GIF to JPG free right in your browser. No server upload, adjust JPEG quality, resize, background color for transparency, capture animation frames, and convert many files at once.
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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.