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.
Liter to cc Converter - Convert Liters to cc and cc to Liters
Free liter to cc converter: convert liters to cc (cubic centimeters) and cc to liters with exact factors, plus mL, cubic inches and US fluid ounces. 1 liter = 1,000 cc exactly.
Liter to Kg Conversion – Density & Energy Converter
Liter to kg conversion, units conversion, lt to kg converter, kg to l conversion, lb gal to kg m3, kg l to lb gal, pcf to kg m3, ft3 to kg, kg to m cubed, j to kwh conversion, kgm to ft lbs, how to convert to kj, lb in 3 to kg m 3, convert therms to kwh, convert kwh to mmbtu, kilowatt hour to btu conversion, kg m 3 to lbs in 3, kwh to mmbtu conversion, btu to kwh calculator, kilogram to cubic meter, kilowatt conversion, convert ft3 to lbs, kgs to cubic meter, btu to kw conversion calculator, lbs ft 3 to kg m 3, how to convert kgs to litres, convert mw to kwh, 1 kg to m 3, kilograms to cubic meters calculator, convert kg per cubic meter.
Liters to Moles Calculator: Convert Gas Volume to Moles at STP
Free liters to moles calculator: convert gas volume to moles at STP (22.414 L/mol) or with custom pressure and temperature via PV=nRT, plus liquid mode using density and molar mass. Formulas, tables, and worked examples.
Liters to Pounds Converter - L to lb Calculator
Convert liters to pounds with this free L to lb calculator. Pick from 14 liquid densities or enter a custom density. Includes conversion tables, the liters to pounds formula, worked examples, and answers to common questions.
LLC Cost by State 2026 — Filing Fees, Annual Fees & 5-Year TCO Calculator | LLC Cost Lab
How much does an LLC cost? Compare LLC filing fees and annual fees for all 50 states + DC, calculate 1/5/10-year total cost of ownership, rank the cheapest states, avoid the Delaware/Wyoming foreign-qualification trap, and estimate NY publication costs. Free, 100% client-side.
LMTD Calculator — Log Mean Temperature Difference for Heat Exchangers | nrtechstudio.com
Free LMTD calculator: compute log mean temperature difference for counter-flow and parallel-flow heat exchangers, the Bowman–Mueller–Nagle correction factor F for 1-shell-pass exchangers, heat duty Q = U·A·F·LMTD, and NTU–effectiveness. 100% in-browser, no sign-up.
Loan Amortization
Calculate loan payments, amortization schedule, and extra principal payoff savings.
Personal Loan Calculator & Amortization Suite
Full-featured loan calculator with amortization schedule, extra payments, balloon payment support, auto/student/business loan presets, and multi-frequency payment modes.
Loan Comparison Calculator — Compare Loans Side by Side
Free loan comparison calculator: compare up to 4 loan offers side by side — monthly payment, total interest, total cost, effective APR with fees, points break-even, and true cost if you exit early. 100% private, runs in your browser.
Loan Constant Calculator & Mortgage Debt Service Studio
Interactive loan constant calculator, home loan interest rate calculation, and credit home loan calculator for real estate investors.
Local Anesthetic Max Dose Calculator — Weight-Based mg & mL (7 Agents)
Free local anesthetic maximum dose calculator: weight-based limits (mg/kg) for lidocaine, bupivacaine, ropivacaine, mepivacaine, prilocaine, articaine and chloroprocaine, with or without epinephrine. Get max mg, max mL, and dental cartridges. Educational estimate only.
Local Business Schema Markup Generator
Interactive Schema.org LocalBusiness JSON-LD generator with address, geo-coordinates, opening hours, and Google SERP preview.
Loft Size Calculator: Mezzanine Area, Headroom, Stairs, Guards & Loads | nrtechstudio
Loft size calculator: max mezzanine area under the 1/3 rule, headroom checks, stair geometry, guard sizing, floor loads and ventilation. Free.
Log Base 2 Calculator (log2) — Change-of-Base Steps | NR Tech Studio
Free log base 2 calculator: enter x to get log2(x) with step-by-step change-of-base work (ln x / ln 2), a 2^log2(x) = x verification check, and related values.
Log Reduction Calculator — CFU, % Kill, D-Value & Dilution
Free log reduction calculator: convert CFU counts to log reduction and percent kill, log↔percent table (1–8 log), D-value contact time, and serial-dilution cumulative log reduction.
Log Weight Calculator — Single Log, Truckload & Species Density Table
Free log weight calculator: weight of a single log from diameter, length and species density (green vs dry). Truckload planner plus species density ta
Logarithm Equation Calculator — Solve log_b(x)=c & Multi-Term Log Equations | NR Tech Studio
Free logarithm equation calculator: solve log_b(x)=c, combine multi-term log equations with automatic extraneous-root rejection (domain check), and evaluate logs via change of base. 100% client-side.
Long Addition Calculator with Steps — Column Addition & Carry Visualization | nrtechstudio.com
Free long addition calculator with steps: add 2 or more numbers (decimals supported) and see every column, every carry, and every intermediate step explained like on paper.
Long Division Calculator with Steps | NR Tech Studio
Free long division calculator with step-by-step working: quotient, remainder, decimal expansion with repeating-decimal detection, and 4 worked examples. 100% client-side, no sign-up.
Long Multiplication Calculator with Steps — Partial Products
Free long multiplication calculator with steps. Multiply two whole numbers and see every partial product per digit, the columnar layout, and full carry-by-carry work.
Long Subtraction Calculator with Steps — Column Method & Borrowing
Free long subtraction calculator with step-by-step column method. See borrowing across every digit, worked examples, and handle negative results.
Long-Term Care Insurance Calculator & Care Cost Estimator — nrtechstudio
Estimate US long-term care (LTC) insurance premiums, nursing home, assisted living, and home care costs, compare two policy scenarios, plus a daily-benefit solver. Educational estimates.
Lorem Ipsum Generator & Dummy Text Generator
Standalone lorem ipsum generator, dummy text generator, placeholder text generator, latin text generator, random text generator, fake text generator, and lipsum generator. Generate lorem ipsum text, sample text, and lorem ipsum dolor sit amet with zero AI slop.
Lorentz Force Calculator - F = q(E + v×B), Electric & Magnetic Force Solver
Free Lorentz force calculator: F = q(E + v×B). Solve electric force qE (3-way), magnetic force qvB·sinθ (5-way), combined E+B fields, cyclotron radius r = mv/qB and orbital frequency f = qB/2πm — elec
Lottery Annuity Calculator — Lump Sum vs Annuity (Powerball & Mega Millions)
Lottery payout calculator: compare lump sum vs 30-year annuity with real 2026 federal tax brackets, state taxes, present value, and a break-even discount-rate solver. Powerball & Mega Millions presets.
Lowest Terms Fraction Calculator - Reduce Fractions to Simplest Form
Reduce any fraction to lowest terms. Shows the GCD with full Euclidean algorithm steps, the simplified fraction, mixed-number form, and decimal value. 100% free, runs in your browser.
LRINEC Score Calculator — Necrotizing Fasciitis Risk (Wong 2004)
Free LRINEC score calculator (Laboratory Risk Indicator for Necrotizing Fasciitis, Wong et al. 2004): 6 lab criteria, risk bands, and lab unit convers
LTV (Loan-to-Value) Calculator — Compute Loan-to-Property-Value Ratio
Free LTV calculator: compute loan-to-value ratio from loan and property value, two-way loan/down-payment solver, 2-scenario DP comparator, and a running-LTV tracker toward 80%. 100% client-side.
Luhn Algorithm Validator
Free Luhn algorithm (mod 10) validator with digit-by-digit steps, card type detection, check digit generator, and batch mode. 100% client-side.
Lumens to Lux Calculator — Convert Lumens to Lux (with Area) | nrtechstudio
Free lumens to lux calculator: E(lux) = lumens / area(m²). Also lux to lumens, foot-candle mode, room planner with recommended lux per room, formulas, charts and worked examples. 100% client-side.
Lumpsum Plus SIP Calculator — One-Time + Monthly Investment Growth
Free lumpsum plus SIP calculator (India): combine a one-time investment with monthly SIP, annual step-up, inflation-adjusted corpus, scenario comparison and year-by-year growth. Also works as a lump sum and SIP calculator / SIP with initial investment calculator.
Lumpsum Calculator — One-Time Investment Growth Projector
Free lumpsum calculator: project the future value of a one-time investment with scenario comparison (8/12/15%), year-by-year growth table, inflation-adjusted real value, INR + USD dual currency, and goal solvers. 100% client-side.
Lung Nodule Growth Rate Calculator — Volume Doubling Time (Free)
Free lung nodule growth rate calculator: volume doubling time (VDT) from two CT volumes or diameters (Schwartz 1961), mass doubling time, growth %/day
MAC Address Converter & Formatter
Standalone professional MAC address converter, formatter, and identifier. Convert between colons, hyphens, Cisco dots, raw hex, and inspect OUI vendors and EUI-64 addresses.
MAC Address Formatter & Editor
Professional MAC address editor, normalizer, and batch formatter tool supporting Cisco, Windows, Linux, and EUI-48 formats.
MAC Address Generator — Random with Custom OUI
Free online MAC address generator: random unicast MAC-48 and EUI-64 addresses with custom OUI prefix, vendor presets, colon/hyphen/Cisco formats, bulk up to 100, validator and decoder. 100% client-side.
Mach Number Calculator - M = v/a with ISA Altitude Model
Free Mach number calculator: 3-way solver (Mach, airspeed, speed of sound) with a=√(γRT) from temperature or ISA altitude 0–20 km, flow-regime readout, and 5 speed units. 100% in-browser, no sign-up.
Macrame Cord Calculator — How Much Cord Do I Need?
Free macrame cord calculator: enter your project and knot type to get cut length per cord, total cord needed, spool recommendations and a printable cutting list. Wall hangings, plant hangers, bracelets, curtains, table runners, bags & more.
MAD Calculator — Mean & Median Absolute Deviation
Free MAD calculator: compute mean absolute deviation, median absolute deviation, and scaled MAD ×1.4826 from any pasted dataset, with per-point deviation tables and an outlier-robustness demo.
MAGI Calculator 2026 — Modified Adjusted Gross Income Calculator
Free MAGI calculator for 2026: compute Modified Adjusted Gross Income (MAGI) from AGI with IRS add-backs, and check Roth IRA, Traditional IRA, student loan interest, and education credit eligibility.
Magnetic Declination Calculator - True North vs Magnetic North (WMM2025)
Free magnetic declination calculator using the official WMM2025 World Magnetic Model. Enter latitude, longitude and date to get compass declination (E/W), annual change, inclination, and true-vs-magne
Magnetic Force on a Current-Carrying Wire Calculator — F = I·L·B·sinθ 5-Way Solver
Free magnetic force on a current-carrying wire calculator: F = I·L·B·sinθ (Ampère force). 5-way solver (F, I, L, B, θ), square-loop mode with per-side
Magnitude of Acceleration Calculator - |a| from Components or Δv/Δt
Free magnitude of acceleration calculator: |a| = sqrt(ax^2 + ay^2 + az^2) from 2D/3D components with direction angles, or from change in velocity a = (v2-v1)/dt. Results in m/s^2, g-force, ft/s^2, km/
Magnus Force Calculator - Spinning Ball Lift, Spin Ratio & CL Curve
Free Magnus force calculator for spinning balls: F = 1/2 rho v^2 A CL from the spin ratio S = omega*r/v, direction readout (topspin/backspin/sidespin), force vs gravity ratio, ball presets (baseball,
Pediatric Maintenance Fluids Calculator — Holliday-Segar & 4-2-1 Rule
Free pediatric maintenance fluids calculator: Holliday-Segar 100-50-20 daily volume and 4-2-1 hourly rate from weight (kg/lb), tiered breakdown, quick reference table, and FAQs. Educational — not medical advice.
Make Text Upside Down – Reverse String & Text Transformer
Make text upside down, alphabetical order creator, reverse alphabet, help in morse, speech reverse, morse translator audio, binary code creator, create upside down text, how to invert words in word, reverse the sentence, upside down and backwards text, sentence reverser, upside down text gen, reverse alphabetical order, reverse string online, write backwards text, numbers to words code translator, reverse writer, written in reverse, font backwards generator, reverse characters, alphabet reversed, reverse alphabet translator, reverse alphabet decoder, backward word translator.
Malus's Law Calculator — I = I₀cos²θ, Polarizer Intensity Solver | nrtechstudio
Free Malus's law calculator: I = I₀·cos²θ three-way solver (I, I₀, θ), multi-polarizer chain with relative angles,
Man-Hours Calculator: Project Work Hour Estimation — nrtechstudio
Free man-hours calculator: compute total project man-hours from workers × hours/day × days, with team & duration solver, compare 2 staffing plans, and labor cost estimation. 100% in the 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.