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.
Free GIF to PNG Converter — Lossless, No Upload
Convert GIF to PNG free right in your browser. 100% client-side, no upload, lossless output, preserved transparency, 10–200% resize, multi-frame sequence mode, and batch conversion.
Gift of Equity Calculator — Mortgage Equity Gift
Calculate property gift of equity: gift value, effective purchase price, LTV on two bases, cash down-payment need, with-vs-without gift comparator, and document completeness check.
Gini Coefficient Calculator — Measure Inequality & Lorenz Curve
Compute the Gini coefficient from raw data, draw the Lorenz curve (SVG), and compare two distributions. Free, 100% in-browser, no data upload.
Git Ignore Generator & Fixer Tool
Interactive .gitignore generator and troubleshooting assistant for git ignore not working, cache clearing, and rule syntax.
.gitignore Generator & File Template
Free online gitignore generator to create .gitignore files for Node.js, Python, Java, React, Laravel, .NET, Android, and Rust. Includes gitignore syntax reference, how to use gitignore, gitignore for directory and folder examples.
Glitch Font Generator & Zalgo Horror Text Maker
Interactive glitch font generator, demonic text maker, broken text converter, and random word generator from letters.
eGFR Calculator (CKD-EPI 2021) — Glomerular Filtration Rate & CKD Stages
Free eGFR calculator using the race-free CKD-EPI 2021 equation. Enter age, sex and serum creatinine to get estimated GFR (mL/min/1.73m²), KDIGO G1–G5
Glycemic Load Calculator — GI, GL & Meal Builder | nrtechstudio
Free glycemic load (GL) calculator: GL = GI x carbs / 100. 42-food GI database, meal GL builder, and GL vs GI explainer with classification bands.
GMROI Calculator — Gross Margin Return on Investment
Free GMROI (Gross Margin Return on Investment) calculator: compute gross margin per inventory rupiah, margin% × turnover conversion, target solver, and two-product comparator.
go.mod Generator
Free online go.mod generator: build a valid Go module file with module path, Go version, require (direct/indirect), replace, exclude, retract and toolchain directives — 100% client-side.
Goat Gestation Calculator — Kidding Due Date, Timeline & Planner | nrtechstudio.com
Free goat gestation calculator: enter the breeding date to get an honest kidding due-date window (145–155 days), live countdown, milestone timeline, reverse breeding planner, multi-doe herd planner, kidding signs checklist and printable kidding kit list. 100% client-side.
God Name Generator – Greek, Celestial & Deity Generator
God name generator, greek name generator, deity name generator, celestial name generator, random greek name generator.
Gold Melt Value Calculator — Scrap Gold Worth by Karat
Calculate the melt value of gold jewelry and scrap by weight (grams, pennyweights, troy ounces) and karat. Multi-item totals, refiner payout %, karat comparison. Free, private, works offline.
Golden Ratio Calculator Online
Free golden ratio calculator, golden section ratio calculator, and golden proportion calculator. Calculate golden ratio dimensions, rectangles, typography, and UI design layouts.
Golden Rectangle Calculator — Sides, Area, Perimeter & Diagonal from φ | nrtechstudio
Free golden rectangle calculator: solve short side, long side, area, perimeter and diagonal from any single value (b/a = φ ≈ 1.618034). With nested-squares and golden-spiral diagram. 100% client-side.
Tool - Golden Spiral Dimension Calculator
Interactive Golden Ratio, Golden Spiral, and Golden Rectangle dimension calculator with live visual canvas, Fibonacci layout scale, and typographic sizing.
Golf Club Distance Calculator: Full Bag Mapping by Swing Speed | nrtechstudio.com
Golf bag distance calculator: carry + total for all 14 clubs from swing speed, editable smash factor, gap analysis, wind/elevation adjusters. Free.
Golf Handicap Calculator (WHS) — Handicap Index, Course & Playing Handicap
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AdSense Calculator: Revenue Estimate, RPM & Target Simulation (Free)
AdSense revenue calculator: estimate earnings from pageviews, CTR & CPC, simulate pageviews for an income target, compute RPM, compare two scenarios. Free.
Gorlin Formula Calculator — Aortic & Mitral Valve Area + Hakki
Free Gorlin formula calculator: estimate aortic valve area (AVA) and mitral valve area (MVA) from cardiac catheterization data, plus the Hakki shortcut, guideline-based stenosis classification, variable explanations, and worked cath-lab examples. Educational only — not medical advice.
Gout Diagnosis Calculator — ACR/EULAR 2015 Classification Scorer (Free)
Free gout classification calculator using the 2015 ACR/EULAR criteria (Neogi et al.): score joint pattern, episode characteristics, time course, tophu
GPA Calculator Suite — Semester, Cumulative & What-If GPA Planner | nrtechstudio.com
Free GPA calculator suite: semester GPA, cumulative GPA, what-if grade planner, 4.0/5.0/percentage scales, and international GPA conversion (German, UK, India, France). 100% private — all math runs in your browser.
Pakistan GPA Calculator (HEC) — Percentage to GPA, Semester GPA & CGPA
Free Pakistan GPA calculator using official HEC bands: percentage to GPA, semester GPA, CGPA, what-if planner, and Pakistan to US GPA converter. 100% client-side.
Gr to mL Converter: Grams to Milliliters Calculator
Free gr to ml converter: convert grams to milliliters and milliliters to grams for water, flour, sugar, butter, honey, oil, milk and lab chemicals. Verified density table, custom density, and a step-by-step breakdown of every calculation.
Grams to Teaspoons Converter (g to tsp) by Ingredient
Convert grams to teaspoons and teaspoons to grams for flour, sugar, salt, butter, honey, baking powder, baking soda and 6 more ingredients. Uses 1 US teaspoon = 4.92892159375 mL with verified densities.
Grade Curve Calculator: Square Root, Linear, Bell Curve and Flat Add - nrtechstudio
Free grade curve calculator: apply square-root, linear scale, bell-curve z-score, or flat-add curves to test scores. See per-student results and the A-F distribution shift. 100% client-side.
Gradient Color Combination & CSS Gradient Studio
Interactive gradient color combination generator, linear & radial gradient maker, 3-color mixer, CSS text gradient, and photo palette extractor.
Gradient Color Combo & Palette Matcher
Interactive gradient generator, color matching application, split complementary harmonies, WCAG accessibility checker, and skin tone generator.
CSS Gradient Generator & Maker
Professional multi-color CSS gradient maker, linear and radial gradient builder, dark gradient CSS generator, text font gradient, and mesh gradient tool online.
CSS Gradient Generator Online
Free CSS gradient generator online. Color gradient generator, color gradient maker, gradient background maker, gradient background generator, gradient color creator, CSS linear gradient generator, CSS radial gradient generator, CSS text gradient generator, gradient maker online, gradient image generator, create gradient online, gradient editor, gradient bg generator, colour gradient generator, online gradient creator.
Graduation Calculator by Birthday - High School Class Year and College Graduation
Enter your birthday to find your kindergarten start year, high school graduating class, and college graduation year. Cutoff-date aware, with a redshirt (held-back) option.
Graham Number Calculator — Value Investing Stock Valuation
Graham Number calculator: fair value from EPS and BVPS via √(22.5 × EPS × BVPS). Compare vs market price, reverse-solve a variable, compare two stocks.
Grain Bin Calculator — Capacity in Bushels, Pounds & Tons
Free grain bin calculator: enter bin diameter and height (round) or length, width and height (rectangular) to get storage capacity in bushels, pounds, US tons and metric tonnes for corn, wheat, soybea
Grain Conversion Calculator — Bushels, Pounds, Tons, Prices & Moisture Shrink
Free grain conversion calculator: convert bushels to pounds, kg, metric tons and short tons for corn, wheat, soybeans, oats and 6 more grains; convert between grains, convert $/bushel prices, and calc
Gram to Liter Conversion Calculator
Free gram to liter calculator and liter to gram converter with a verified density table (water, milk, oil, honey, gasoline, diesel, ethanol, glycerin, flour), custom density, and US gallon and pint conversion. Shows every step of the calculation.
Grams to Calories Calculator: Protein, Carbs, Fat to Kcal (Atwater System)
Convert protein, carbs, fat, alcohol and fiber grams to kcal with verified Atwater factors. USDA food presets per 100 g, percentage breakdown. Free.
Grams to Fluid Ounces Converter - g to fl oz Calculator
Free grams to fl oz converter. Convert grams to fluid ounces (and fl oz to grams) for water, milk, oil, honey, sugar, flour, salt, or any custom density. US and Imperial fluid ounces supported, with show-your-work formula and conversion tables.
Grams to Kilograms Converter: g to kg Calculator with Formula
Free grams to kilograms converter and kilograms to grams converter. Convert g to kg (divide by 1000) or kg to g (multiply by 1000) with live results, show-your-work steps, quick conversion table, popular conversions, and FAQ.
Grams to Moles Calculator — Convert g to mol & mol to g (Free Chemistry Tool)
Free grams to moles calculator: convert grams to moles and moles to grams using molar mass. Type any chemical formula (e.g. H2SO4) to auto-compute molar mass from 118 elements, or pick from 48 common compounds. Shows every step.
Graphic Display Calculator Online & Scientific Grapher
Free online graphic display calculator (GDC) and scientific graphing calculator. Plot math functions, calculate stats probability, and solve proportions online.
Graphing Calculator Tool & Statistical Central Tendency Studio
Interactive graphing calculator tool, function plotter, find the mode calculator, mean math calculator, and mean median mode generator.
Standalone - Grass Seed Calculator
Grass seed calculator: exact pounds for 20 species - new lawn vs overseeding rates, bag sizes, spreader settings, watering schedule and project cost.
Gratuity Calculator India — Payment of Gratuity Act 1972 Formula
Free gratuity calculator for India: compute gratuity under the Payment of Gratuity Act 1972 with the (salary × 15 × years) ÷ 26 formula, 6-month rounding rule, 5-year eligibility, ₹20 lakh ceiling and tax exemption (govt vs private). 100% private — runs in your browser.
Gravel Calculator — How Much Gravel Do I Need? (Cubic Yards, Tons & Bags)
Gravel calculator: how much gravel do I need? Enter area x depth for cubic yards, tons, bags & cost — multi-layer base/top, waste & compaction
Newton\
Compute Newton's gravitational force between two masses: 4-way solver (F, M, m, r), verified Earth–Sun presets, results in newton/kN/lbf, comparison vs weight on Earth, and an explanation of force vs weight vs g field.
Gravitational Potential Energy Calculator (U=mgh & U=−GMm/r)
Calculate gravitational potential energy: near-surface U=mgh (U/m/g/h solver) and universal U=−GMm/r (U/M/m/r solver), celestial presets, orbit energy.
Greatest Common Factor & Least Common Multiple Calculator
Interactive GCF and LCM calculator with step-by-step prime factorization, Euclidean algorithm breakdown, polynomial LCM, and multi-number support.
Greek Gematria Calculator: Isopsephy Values for Greek Words
Free Greek gematria calculator (isopsephy). Type Greek text, with or without polytonic accents, and get the total numeric value plus a per-letter breakdown. Includes word comparison, a full Greek letter value chart, and verified classic examples such as Jesus = 888.
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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.