Free Finance Tools & Calculators
Browse 356+ free interactive finance calculators, estimators, and utilities. 100% free, private, and runs directly in your browser without signup.
Finance Charge Calculator — TILA Loan & Credit Card Finance Charges
Free finance charge calculator using Truth in Lending (Regulation Z) methodology: installment loan finance charge, credit-card average daily balance method, single-payment loans, and effective APR including fees.
Fixed Asset Turnover (FAT) Calculator — Fixed Asset Efficiency Ratio
Calculate fixed asset turnover (revenue ÷ average fixed assets / net PPE), compare with total asset turnover, compare two companies or two periods, plus interpretation and FAQ. 100% in the browser.
Fixed Deposit (FD) Calculator India — Maturity Value, Interest & Effective Yield
Free fixed deposit calculator for India: estimate FD maturity value, total interest and effective yield. Compare monthly, quarterly, half-yearly and yearly compounding, with senior-citizen rate toggle.
Flange Size Calculator — Breast Pump & ANSI Pipe Flange Sizer
Find your breast pump flange size from nipple mm (Spectra, Medela, Motif, Willow) or look up ANSI B16.5 pipe flange dimensions. Free, in-browser tool.
Florida Overtime Pay Calculator — 1.5× for Hours Over 40
Calculate Florida overtime pay: 1.5× the regular rate for hours over 40/week (federal FLSA rules). Hourly mode, salary→hourly conversion, scenario comparison, and FAQ. Free.
FX Forward Premium & Discount Calculator — nrtechstudio
Calculate FX forward premium/discount from spot & forward rates, 360/365 annualization, forward points (pips), covered interest parity (CIP), and compare two scenarios. Educational estimates.
Interest Rate Forward Rate Calculator — Spot, Bootstrap & FRA
Interest rate forward rate calculator: compute f(t1,t2) from the spot curve, bootstrap inter-period forwards, and simulate FRA payoffs. Free, 100% in the browser.
FCFE Calculator — Free Cash Flow to Equity for Shareholders
Calculate Free Cash Flow to Equity (FCFE) from FCFF or from operating cash flow (CFO), with formulas, verified examples, Gordon valuation, and FAQ.
FCFF (Free Cash Flow to Firm) Calculator — Calculate Company Free Cash Flow
Free FCFF calculator: compute free cash flow to firm from operating cash flow (CFO) or EBIT, with an FCFF-to-FCFE reconciliation bridge. Educational estimates, 100% runs in the browser.
Free Cash Flow (FCF) Calculator — Calculate Free Cash Flow
Free free cash flow (FCF) calculator: compute FCF = operating cash flow − capital expenditure, FCF from net income (indirect method), FCF margin, FCF yield, and compare two companies.
Freelance Rate Calculator — Hourly, Day Rate, IR35 & Contractor Suite
Free freelance rate calculator suite: salary-to-hourly rate with overhead & utilization, day-rate contractor mode, UK IR35 inside-vs-outside take-home, contract-vs-permanent comparator, and US/UK/DE/IN tax presets. 100% client-side.
Fresh Frozen Plasma Dose Calculator (Human & Dog) | nrtechstudio.com
Free fresh frozen plasma (FFP) dose calculator: weight-based dosing for humans (10-15 mL/kg) and dogs (6-20 mL/kg), units needed, infusion time. Educa
Fire Hose Friction Loss Calculator — FL, PDP & Nozzle Pressure | nrtechstudio.com
Free fire hose friction loss calculator. Enter flow (GPM), hose length and diameter to get FL = C(Q/100)²(L/100), pump discharge pressure (PDP = nozzle pressure + friction loss + elevation + appliance loss), FL per 100 ft, and nozzle reaction. Imperial + metric, 100% in-browser.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Gross Margin Calculator — Free
Free gross margin calculator: Rp & percent margin, markup conversion, 3-way target margin solver, A vs B comparator, COGS scenario table. 100% in-browser.
Gross Pay Calculator — Hourly, Salary, Overtime, Bonus, Commission & Tips
Free gross pay calculator: compute gross wages from hourly rate × hours, overtime at 1.5× (FLSA), double time, salary, bonuses, commissions and tips — shown weekly, biweekly, monthly and annually.
Property GRM (Gross Rent Multiplier) Calculator — Free
Free property GRM calculator: compute gross rent multiplier from price and rent, implied price/rent solver, compare 2 properties, GRM vs rental yield.
Growing Annuity Calculator — PV, FV & Solver
Free growing annuity calculator: present value & future value of payments growing g% per period, PMT1/g/r/n solver, growing vs level annuity comparison.
India GST Calculator — Calculate CGST, SGST & IGST (Add, Remove, Compare)
India GST calculator: add GST to base price, remove GST from inclusive price, compare two rates, find effective rate. CGST/SGST/IGST split. Free.
GST QST Calculator Quebec — 5% GST + 9.975% QST (2026)
Free GST QST calculator for Quebec: add or remove 5% GST + 9.975% QST from any price. Exact breakdown, reverse tax calculator, and Canada province comparison.
GTIN Check Digit Calculator (GS1 Modulo 10) — Free, No Signup
Free GS1 GTIN check digit calculator. Compute the modulo-10 check digit for GTIN-8, GTIN-12 (UPC-A), GTIN-13 (EAN-13) and GTIN-14, validate complete GTINs, or batch-process many numbers. 100% client-side.
Health Insurance Plan Comparison Lab — HDHP vs PPO, HSA & Monte Carlo Simulator (2026)
Free health insurance plan comparison calculator: compare two plans side by side, run a Monte Carlo cost simulator, find the break-even spending level, estimate HSA tax savings (2026 IRS limits), and check family vs individual coverage. Educational estimates, 100% client-side.
Hedge Ratio Calculator: Number of Futures Contracts for Hedging
Compute the hedge ratio: number of futures contracts to hedge a spot exposure, optimal hedge ratio h* = ρ × (σ_S/σ_F), and hedge effectiveness. Free, 100% in the browser.
HELOC Calculator — Home Equity Line of Credit Payment Estimator
Free HELOC calculator: estimate your max home equity line of credit from home value and mortgage balance (CLTV), interest-only draw-phase payments, repayment amortization, draw schedules, rate shocks, and HELOC vs cash-out refinance comparison.
Hex Dec Oct Bin Converter — 4 Bases Live at Once | nrtechstudio.com
Free hex / decimal / octal / binary converter: type in any of the four fields and all others update live. Show-your-work steps, 0x/0b/0o prefixes, exact big-integer math. 100% client-side, private.
HHI Calculator (Herfindahl-Hirschman Index) — Measure Market Concentration
HHI calculator: compute the Herfindahl-Hirschman Index from market shares, simulate merger impact, compare two markets, and compute the equivalent number of firms.
High-Low Method Calculator — Split Fixed & Variable Costs
Free high-low method calculator: split mixed costs into fixed cost and variable rate per unit, predict costs, multi-period table analysis, and compare two datasets. Y = a + bX formula with full calculation steps.
Holiday Entitlement Calculator UK
Free UK holiday entitlement calculator: full-time, part-time pro-rata, irregular hours 12.07% accrual, leavers and bank holidays by nation.
Home Affordability Calculator — How Much House Can You Afford?
Calculate the maximum affordable home price from income, debts, down payment, and interest rate. 28/36 rule, PITI breakdown, PMI, rate scenarios, and down payment slider.
Home Equity Loan Calculator — Lump-Sum Fixed-Rate Payment Estimator
Free home equity loan calculator: estimate your max loan from home value, mortgage balance and CLTV cap, fixed-rate amortized monthly payments, total interest, net proceeds after closing costs, and a home equity loan vs HELOC interest-only comparison.
Home Renovation Loan Calculator — Payments, Interest & Scenario Comparison
Calculate monthly payments on a home renovation loan, total interest, maximum-loan simulation from a target payment, compare 2 scenarios, and view the first-12-months amortization table. Free educational estimate.
Home Loan Calculator — Monthly Payment, Interest & Amortization
Free home loan calculator: monthly P&I payment, total interest, full amortization schedule, PITI (taxes + insurance), extra payments and lump-sum prepayments. Also works as a home loan EMI calculator (₹).
Hot Tub Size Calculator — Spa Dimensions, Gallons, Electrical & Space Planner
Hot tub size calculator: pick the right spa by bathers, check space fit, water gallons, filled weight, electrical service & steps. 7 free planning too
House Flipping Calculator — Fix & Flip Deal Analyzer (70% Rule + MAO)
Free house flipping calculator: fix & flip deal analyzer with the 70% rule, maximum allowable offer (MAO), rehab budget line-items, holding cost engine, 3-deal comparison and flip tax estimator. 100% client-side, no signup.
How Much Loan Can I Afford? — Personal Loan Affordability Calculator
Free personal loan affordability calculator: enter your income, existing debts, APR and term. It applies a debt-to-income (DTI) cap and reverses the loan formula to the maximum loan you can afford.
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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.