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.
TIMI Risk Score Calculator for UA/NSTEMI — 14-Day Composite Risk (Antman 2000) — NR Tech Studio
TIMI risk score calculator for unstable angina/NSTEMI (Antman 2000): 7 variables at 1 point each, total 0–7, 14-day composite risk estimates, risk table, GRACE/HEART comparison, and clinical FAQ. Educational tool — not medical advice.
Tinetti (POMA) Calculator — Elderly Fall Risk Test
Interactive Tinetti POMA (Performance Oriented Mobility Assessment) calculator: 16 balance and gait observation items, 0–28 score, real-time subtotals, and fall risk categories.
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.
ACR TI-RADS Calculator — Thyroid Nodule Classification from Ultrasound
ACR TI-RADS (2017) calculator: score 5 thyroid nodule ultrasound features, determine TR1–TR5 level, FNA & ultrasound follow-up thresholds, plus a multi-nodule tracker.
Tire Pressure Calculator — Load-Based PSI, New Tire Size, Temperature Altitude
Free tire pressure calculator: load-based cold inflation (TRA power rule + Daws stiffness model), new tire size / plus-size pressure correction, temperature and altitude adjustment, psi/bar/kPa converter and MPG impact estimator. 100% client-side.
Tire Size Calculator & Comparison — Speedometer Error, Will-It-Fit & Visualizer (Free)
Free tire size calculator and comparison tool: compare two tire sizes side by side, calculate speedometer & odometer error, revolutions per mile, gear ratio effect, will-it-fit verdict, visual overlay, load index & speed rating charts. Metric, flotation, motorcycle & bicycle sizes. 100% client-side, no signup.
Title Tag Len
Check SEO title character and pixel width.
TNT Equivalent Calculator — Energy to kg of TNT, Explosives & Pressure Vessels
Free TNT equivalent calculator: convert any energy (J, kJ, MJ, kWh, MWh, BTU) to kilograms of TNT, convert TNT mass back to energy, compare explosives with TNT equivalence factors (RDX 1.6, PETN 1.66, ANFO 0.82), estimate compressed-gas pressure-vessel burst energy, and compare with real events from
TOML to JSON Converter
Free online TOML to JSON converter — paste TOML or upload a .toml file, get pretty or minified JSON instantly with syntax highlighting, validation, and line-number error messages. 100% client-side.
Ton to kW Converter — Convert Tons of Refrigeration (TR) to kW
Free ton to kW converter: convert tons of refrigeration (TR) to kW, BTU/hr, kcal/h, HP and back. Exact definition 1 TR = 3.5168525 kW = 12,000 BTU/hr, plus AC room-sizing and EER/COP helpers.
Free Online Developer Tools Hub & Suite
Master directory of 400+ free online developer tools, converters, calculators, and high performance web utilities with zero latency.
Torque Calculator: Solve Torque, Force, Lever Arm, Angle
Torque calculator: solve tau = r x F x sin(theta) in all 4 directions (torque, lever arm, force, angle), with torque unit converter (N m, kN m, ft lb,
Torsional Constant Calculator: J for Solid, Hollow and Thin-Walled Sections
Free torsional constant (J) calculator: solid shaft J = pi d^4/32, hollow shaft, thin-walled open and closed sections (Bredt formula), diameter solver
Torsional Spring Calculator: Spring Rate, Torque, Deflection and Wahl Stress
Free torsional spring calculator: helical torsion spring rate k = E*d^4/(64*D*Na), torque/deflection/rate solver, Wahl-corrected bending stress, coil
TOTP Generator — Free 2FA Code Generator Online (SHA-1/SHA-256/SHA-512 + Validator)
Free online TOTP generator: create time-based one-time passwords (2FA codes) in your browser. SHA-1, SHA-256, SHA-512, 6/8 digits, live countdown, code validator, otpauth:// import. 100% client-side — your secret never leaves your device.
Towing Capacity Calculator — Payload, GCWR & Tongue Weight Safety Check (Free)
Free towing capacity calculator with dual-constraint safety solver: checks tow rating, GCWR, payload capacity and tongue weight (10–15% / 15–25% for 5th wheel & gooseneck), finds your binding limit, and gives a green/yellow/red safety verdict. 100% client-side, no signup.
Tongue Weight Calculator & Trailer Towing Lab — Free 6-in-1 Tool
Free trailer towing & tongue weight lab: tow-vehicle match check (GVWR, payload, GCWR, GAWR), tongue weight calculator from CAT scale readings, fifth-wheel pin weight, weight-distribution-hitch advisor, trailer weight guide and water-tank tongue shift. 100% client-side, no signup.
Town Name Generator – Fantasy Place & City Generator
Town name generator, fantasy place name generator, fantasy location name generator, random town name generator, fake country name generator, made up city names generator.
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.
Tramadol Dosage Calculator for Dogs — mg by Weight + 50 mg Tablet Splits (q8h)
Estimate tramadol dose for dogs by weight per the veterinary label: 2-4 mg/kg every 8 hours, max 16 mg/kg/day — with 50 mg tablet quarter-splits always rounded down. Educational estimate, not veterina
Trampoline Size Calculator — Yard Fit, Clearance & Jumping Surface Planner
Trampoline size calculator with 7 modes: yard fit, clearance rules (ASTM F2225, JumpSport, Springfree), jumping surface, overhead check and ground pre
Transferrin & Iron Studies Calculator — TSAT, UIBC, Ferritin
Free transferrin & iron studies calculator: calculate transferrin saturation (TSAT) and UIBC from serum iron & TIBC, convert units µg/dL ⇄ µmol/L, integrated TSAT + ferritin interpretation panel. 100% client-side.
Transformer Sizing Calculator — kVA, Full-Load Amps, Turns Ratio
Free transformer sizing calculator: full-load current 1-phase & 3-phase both ways, kVA sizing from load kW with NEC 25% margin, standard kVA sizes, turns ratio, impedance %Z short-circuit current, and inrush notes. 100% client-side.
CMYK to Pantone Calculator, HSL Color Picker & Hex Translator
Free online CMYK to Pantone calculator and HSL color picker. Translate CMYK to Pantone, convert Pantone color to hex, hex translator color, change rgba to hex, and explore hexadecimal color guide.
Trapezoidal Prism Volume Calculator — Formula, Surface Area & Worked Steps
Free trapezoidal prism volume calculator: enter the two parallel bases, trapezoid height and prism length to get volume, base area, surface area and step-by-step working.
Tree Age Calculator — Estimate Age by DBH, Circumference or Ring Count | nrtechstudio.com
Free tree age calculator: estimate a tree
Tree Benefits Calculator — CO2, Stormwater, Cooling & Air Quality
Estimate a tree's annual ecosystem benefits i-Tree style: CO2 sequestered and stored (Jenkins 2003 biomass), stormwater intercepted (Xiao & McPherson), cooling energy saved, and air pollutants removed
Tree Diameter Calculator (DBH) — Measure, Convert & Basal Area
Free tree diameter (DBH) calculator: convert tape circumference to diameter, diameter to circumference and basal area, combine multi-stem trunks, and estimate plot basal area per acre. Imperial and me
Tree Spacing Calculator: Trees per Acre & Hectare
Free tree spacing calculator: find trees per acre or hectare from spacing in feet or meters, square, rectangular, or triangular planting. Reverse mode, species presets, loss allowance, reference chart.
Tree Value Calculator — Amenity & Timber Value (Trunk Formula) | nrtechstudio
Free tree value calculator: estimate your tree
Treehouse Size Calculator — 7 Free Planning Tools | nrtechstudio
Free treehouse size calculator: tree DBH check, platform size, railing height, ladder angle, deck load, TAB anchor size and joist spans — 7 tools in o
Trellis Size Calculator — Garden Trellis Planner, Posts, Lattice & Cost
Plan the perfect garden trellis: size by plant type, post and burial depth, lattice spacing, wind bracing, material takeoff and cost. Free 7-in-1 planner.
Tool - Triangle Area Calculator & Trigonometry Angle Solver
Universal triangle calculator featuring triangle area calculator, area right triangle calculator, trig functions calculator, and trigonometry angle calculator with live canvas diagram.
Law of Cosines Calculator — Solve SSS & SAS Triangles | NR Tech Studio
Free law of cosines calculator: find all three angles from three sides (SSS), or the third side from two sides and the included angle (SAS). Shows substitution steps and a labeled diagram. 100% client-side.
Law of Sines Calculator — Solve Triangles with a/sin A = b/sin B = c/sin C
Free law of sines calculator: solve ASA/AAS triangles and the tricky SSA ambiguous case (0, 1, or 2 solutions) with steps and a live diagram.
Triangle Perimeter Calculator — 3 Sides or 3 Points (Free, Steps Shown)
Free triangle perimeter calculator: enter 3 side lengths or 3 coordinates (x, y) to get the perimeter P = a + b + c, with honest triangle-inequality validation, a labeled SVG diagram, and step-by-step working. 100% client-side.
Triangular Pyramid Volume Calculator — Volume, Heron Base & Surface Area
Free triangular pyramid volume calculator: enter the triangle base (equilateral edge, base × height, or 3 sides via Heron's formula) and the pyramid height to get volume V=⅓×A×h, plus slant height and surface area for regular pyramids, with diagram and step-by-step working.
Trigonometry Calculator
Trigonometry calculator, trigonometric equations calculator, trig calculator online, sine and cosine calculator, trig value calculator, find trigonometric functions calculator, math trigonometry calculator.
Trihybrid Cross Punnett Square Calculator — 64-Box Grid, 27:9:9:9:3:3:3:1
Free trihybrid cross Punnett square calculator: enter two parent genotypes (AaBbCc x AaBbCc), get the 64-box grid, 27:9:9:9:3:3:3:1 phenotypic ratio, exact genotype probabilities, and a phenotype-prob
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.
True Strain Calculator - ln(1+e), True Stress
Free true strain calculator: epsilon_t = ln(L/L0) = ln(1+epsilon_e), engineering-to-true strain conversion, true stress sigma_t = sigma_e(1+epsilon_e). Units: %, mm/m, microstrain.
TSConfig Generator
Free online tsconfig.json generator: presets for Node, React, Next.js, libraries and monorepos, visual compilerOptions builder, and tsc-accurate validation.
TSV to CSV Converter - Free Online One-Way Tool
Free TSV to CSV converter: RFC 4180 quoting, delimiter picker, live table preview, file upload, download. One-way tsv to csv only. 100% client-side.
TTKG Calculator (Transtubular Potassium Gradient) — Hyperkalemia & Hypokalemia Interpretation
Calculate TTKG = (urine K / serum K) × (serum osmolality / urine osmolality) with automatic validity checks, hyperkalemia vs hypokalemia interpretation tree, differential diagnosis table, and unit converter. Educational aid.
Turbo Size Calculator — Turbocharger Sizing, Airflow (lb/min), Pressure Ratio & Compressor Map Position
Size a turbocharger from target HP: required airflow in lb/min and CFM (Garrett Turbo Tech 103 formula), pressure ratio, boost required, frame-class recommendation (GT28/GT30/GT35/GTX) and surge/choke warnings. Gas, diesel and E85 presets.
Turkey Defrost Calculator — USDA Thawing Times (Fridge, Cold Water, Microwave)
Free turkey defrost calculator: USDA-based thawing times for refrigerator (24h per 4-5 lb), cold water (30 min per lb) and microwave methods, plus a reverse planner that tells you when to start thawing.
Turkey Size Calculator — How Much Turkey Per Person | nrtechstudio.com
Holiday turkey planner: size per person, thaw time, roast, fry and smoke times at USDA-safe 165°F, plus side-dish scaling. Free tool, runs in your browser.
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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.