70+ free calculators & converters as MCP tools; each result links to its source page.
Scored across 74 tools
Most tools are clearly distinct, with each converter or calculator targeting a unique concept. However, `file_hash` and `hash_generator` are essentially identical (both hash text via SHA-1/256/384/512), and several CSV/TSV tools could be confused despite differing outputs.
Names largely follow a predictable `[concept]_[action]` pattern with suffixes like `_calculator`, `_converter`, and `_generator`, making the suite readable. A few outliers such as `base64`, `lorem_ipsum`, `transliteration`, and `number_base` break the pattern but are still intuitive.
With 74 tools, the server far exceeds the recommended size for an MCP toolsetall. Even as a general utility collection, the extreme count overwhelms agent selection and introduces avoidable ambiguity, falling into the 50+ extreme mismatch category.
The toolset covers a broad range of unit converters, calculators, text utilities, and generators, leaving few obvious gaps for its stated purpose. Minor omissions like a frequency converter or currency exchange are easily worked around and not critical to the domain.
Exact age in years, months and days between a birth date and a reference date (default: today). Runs on smart-tools.xyz.
Inputs: birth_date (required), locale, at_date.
Convert a value between angle units. Units: ° (Degree), rad (Radian), grad (Gradian), mrad (Milliradian), rev (Turn), ′ (Arcminute), ″ (Arcsecond). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
Convert a value between area units. Units: km² (Square kilometer), m² (Square meter), cm² (Square centimeter), mm² (Square millimeter), ha (Hectare), ac (Acre), mi² (Square mile), ft² (Square foot), yd² (Square yard), in² (Square inch). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
Simplify a width×height ratio and scale to a new width or height. Runs on smart-tools.xyz.
Inputs: width (required), height (required), locale, new_width, +1 more.
Encode text to Base64 or decode Base64 back to text, UTF-8 safe, with an optional URL-safe alphabet. Runs on smart-tools.xyz.
Inputs: text (required), locale, url_safe, direction.
Body Mass Index and category. system=metric: weight_kg, height_cm. system=imperial: weight_lb, height_ft (+height_in). Runs on smart-tools.xyz.
Inputs: locale, system, height_cm, height_ft, +3 more.
Basal metabolic rate (Mifflin–St Jeor) and daily calories (TDEE = BMR × activity). Runs on smart-tools.xyz.
Inputs: age (required), sex (required), height_cm (required), weight_kg (required), +2 more.
Body fat percentage by the US Navy (Hodgdon–Beckett) method, metric measurements in cm. Females require hip_cm. Runs on smart-tools.xyz.
Inputs: sex (required), neck_cm (required), waist_cm (required), height_cm (required), +2 more.
Convert text to UPPER, lower, Title, Sentence, camelCase, PascalCase, snake_case, kebab-case or CONSTANT_CASE. Runs on smart-tools.xyz.
Inputs: case (required), text (required), locale.
Convert a color between HEX, RGB and HSL. Accepts #hex, rgb()/rgba(), hsl()/hsla(). Runs on smart-tools.xyz.
Inputs: color (required), locale.
Future balance and interest earned: A = P(1 + r/n)^(nt). Runs on smart-tools.xyz.
Inputs: years (required), principal (required), annual_rate (required), locale, +1 more.
Parse a 5-field cron expression (minute hour day-of-month month day-of-week) into a plain-English description. Runs on smart-tools.xyz.
Inputs: expression (required), locale.
Parse CSV/TSV text (auto-detecting tab, semicolon or comma delimiter) with a header row into an array of JSON objects. Runs on smart-tools.xyz.
Inputs: text (required), locale, has_header.
Turn CSV/TSV rows into SQL INSERT statements with standard double-quoted identifiers and escaped values. Runs on smart-tools.xyz.
Inputs: text (required), nulls, locale, quote_all, +3 more.
Convert a value between data units. Units: bit (Bit), B (Byte), kB (Kilobyte), MB (Megabyte), GB (Gigabyte), TB (Terabyte), KiB (Kibibyte), MiB (Mebibyte), GiB (Gibibyte), TiB (Tebibyte). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
Difference between two dates: calendar years/months/days, total days, weeks and weekday count. Runs on smart-tools.xyz.
Inputs: end_date (required), start_date (required), locale.
Final price after one or two successive discounts, plus amount saved. Runs on smart-tools.xyz.
Inputs: price (required), discount (required), locale, second_discount.
Estimated due date by Naegele's rule (+280 days from last period, adjusted for cycle length). Runs on smart-tools.xyz.
Inputs: last_period (required), locale, cycle_length.
Running cost of an appliance per day, month and year from its wattage. Runs on smart-tools.xyz.
Inputs: power_watts (required), hours_per_day (required), price_per_kwh (required), locale.
Convert a value between energy units. Units: J (Joule), kJ (Kilojoule), cal (Calorie), kcal (Kilocalorie), Wh (Watt-hour), kWh (Kilowatt-hour), BTU (British thermal unit), ft·lb (Foot-pound), eV (Electronvolt). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
Compute a SHA-1/256/384/512 hex checksum of provided text or base64 bytes. Runs on smart-tools.xyz.
Inputs: data, text, locale, algorithm.
Exact arithmetic on two fractions (a/b op c/d), reduced to lowest terms. op is one of + - * /. Runs on smart-tools.xyz.
Inputs: a (required), b (required), c (required), d (required), +2 more.
Fuel needed and trip cost. system=metric: distance km, consumption L/100km. system=imperial: distance miles, consumption mpg. Runs on smart-tools.xyz.
Inputs: distance (required), fuel_price (required), consumption (required), locale, +1 more.
Build a .gitignore from curated templates for Node, Python, Go, Rust, macOS, VS Code and more. Runs on smart-tools.xyz.
Inputs: technologies (required), locale.
Weighted grade point average from letter grades (US 4.0 scale, +/-) or numeric grade points and credit hours. Runs on smart-tools.xyz.
Inputs: courses (required), locale.
Build a CSS linear or radial gradient background declaration from two or more colors. Runs on smart-tools.xyz.
Inputs: colors (required), type, angle, locale.
Hash text with SHA-1, SHA-256, SHA-384 or SHA-512 (hex, over UTF-8 bytes). MD5 is not supported. Runs on smart-tools.xyz.
Inputs: text (required), locale, algorithm.
Convert a height between centimetres and feet/inches. Give cm, or feet (with optional inches). One inch = 2.54 cm exactly. Runs on smart-tools.xyz.
Inputs: cm, feet, inches, locale.
Time worked between two clock times (handles overnight), minus a break, with optional pay. Times as HH:MM. Runs on smart-tools.xyz.
Inputs: end (required), start (required), locale, hourly_rate, +1 more.
Generate Apache .htaccess rules: force HTTPS, www redirect, caching, gzip, hotlink protection and more. Runs on smart-tools.xyz.
Inputs: www, gzip, cache, locale, +5 more.
Escape the five special HTML characters (optionally all non-ASCII) or decode named and numeric HTML entities back to text. Runs on smart-tools.xyz.
Inputs: text (required), locale, direction, encode_all.
Healthy weight range (BMI 18.5–24.9) plus Devine, Robinson, Miller and Hamwi formula estimates, from height in cm. Runs on smart-tools.xyz.
Inputs: sex (required), height_cm (required), locale.
Validate and pretty-print or minify JSON, reporting the line and column on a parse error. Runs on smart-tools.xyz.
Inputs: text (required), action, indent, locale.
Decode a JSON Web Token's header and payload (base64url). Does NOT verify the signature — that needs the secret/key. Runs on smart-tools.xyz.
Inputs: token (required), locale.
Fix text typed in the wrong keyboard layout between English QWERTY and Ukrainian ЙЦУКЕН. Runs on smart-tools.xyz.
Inputs: text (required), locale, direction.
Convert a value between length units. Units: km (Kilometer), m (Meter), cm (Centimeter), mm (Millimeter), µm (Micrometer), mi (Mile), yd (Yard), ft (Foot), in (Inch), nmi (Nautical mile). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
Monthly payment, total repayment and interest for an amortising loan (annuity formula). Runs on smart-tools.xyz.
Inputs: years (required), principal (required), annual_rate (required), locale.
Generate placeholder lorem ipsum text by paragraphs, sentences or words. Runs on smart-tools.xyz.
Inputs: unit, count, locale, start_lorem.
Profit, margin (share of price) and markup (share of cost) from cost and selling price. Runs on smart-tools.xyz.
Inputs: cost (required), price (required), locale.
Build a padded GitHub-flavored Markdown table from CSV/TSV text (first row is the header). Runs on smart-tools.xyz.
Inputs: text (required), locale.
Generate SEO, Open Graph and Twitter Card HTML meta tags for a page. Runs on smart-tools.xyz.
Inputs: title (required), url, image, locale, +3 more.
Monthly mortgage payment including optional down payment, property tax and insurance (PITI). Runs on smart-tools.xyz.
Inputs: years (required), home_price (required), annual_rate (required), locale, +3 more.
Convert an integer between bases 2–36 (binary, octal, decimal, hex and more), exact for 64-bit values via BigInt. Runs on smart-tools.xyz.
Inputs: value (required), from_base (required), locale, to_base.
Running pace per km and per mile, plus speed, from distance and time. Runs on smart-tools.xyz.
Inputs: distance (required), unit, hours, locale, +2 more.
Generate a cryptographically strong random password with configurable length and character sets. Runs on smart-tools.xyz.
Inputs: digits, length, locale, symbols, +2 more.
Percentage operations. operation=percent_of: a% of b. operation=is_what_percent: a is what % of b. operation=change: percent change from a to b. Runs on smart-tools.xyz.
Inputs: a (required), b (required), operation (required), locale.
Convert a value between pressure units. Units: Pa (Pascal), kPa (Kilopascal), hPa (Hectopascal), bar (Bar), atm (Atmosphere), psi (Pound per sq inch), mmHg (Millimeter of mercury), inHg (Inch of mercury). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
Generate cryptographically random integers in a range, optionally unique and sorted. Runs on smart-tools.xyz.
Inputs: max (required), min (required), count, locale, +2 more.
Test a JavaScript regular expression against text and return every match with its captured groups. Runs on smart-tools.xyz.
Inputs: text (required), pattern (required), flags, locale.
Remove duplicate lines, with optional trim, case-insensitive matching, sorting or keeping only the duplicated lines. Runs on smart-tools.xyz.
Inputs: text (required), sort, trim, locale, +2 more.
Build a robots.txt: allow or block all, custom disallow paths, AI-crawler blocking, crawl-delay and sitemap. Runs on smart-tools.xyz.
Inputs: access, locale, sitemap, block_ai, +2 more.
Convert pay between hourly, daily, weekly, biweekly, monthly and annual. Runs on smart-tools.xyz.
Inputs: amount (required), period (required), locale, hours_per_week, +1 more.
Evaluate a math expression with correct order of operations: + - * / % ^, parentheses, and functions (sqrt, sin, cos, tan, ln, log, exp, min, max, factorial via !). Constants pi, e. Angles in radians. Runs on smart-tools.xyz.
Inputs: expression (required), locale.
Turn text (incl. Ukrainian and accented Latin) into a clean URL slug; each non-empty line becomes its own slug. Runs on smart-tools.xyz.
Inputs: text (required), locale, separator.
Convert a value between speed units. Units: m/s (Meter per second), km/h (Kilometer per hour), mph (Mile per hour), ft/s (Foot per second), kn (Knot). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
Mean, variance and standard deviation (both sample and population) of a list of numbers. Runs on smart-tools.xyz.
Inputs: values (required), locale.
IPv4 subnet details: network, broadcast, mask, wildcard, host range and count for an IP and prefix. Runs on smart-tools.xyz.
Inputs: ip (required), locale, prefix.
Convert a pasted HTML or delimited (tab/semicolon/comma) table into clean CSV. Runs on smart-tools.xyz.
Inputs: text (required), locale.
Convert a value between temperature units. Units: °C (Celsius), °F (Fahrenheit), K (Kelvin), °R (Rankine). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
Count characters (with and without spaces), words, lines, paragraphs and estimated reading time. Runs on smart-tools.xyz.
Inputs: text (required), locale.
Line-level diff of two texts (LCS): counts of added/removed lines plus a marked-up line list. Runs on smart-tools.xyz.
Inputs: a (required), b (required), trim, locale, +1 more.
Convert a value between time units. Units: µs (Microsecond), ms (Millisecond), s (Second), min (Minute), h (Hour), d (Day), wk (Week), mo (Month), yr (Year). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
Convert between a Unix timestamp and an ISO 8601 date (UTC). direction=to_date: epoch → date; to_timestamp: date → epoch. Runs on smart-tools.xyz.
Inputs: value (required), locale, direction.
Tip amount, total and per-person split for a bill. Runs on smart-tools.xyz.
Inputs: bill (required), tip_rate (required), locale, people.
Transliterate Ukrainian Cyrillic to Latin by the official KMU #55 passport standard. Runs on smart-tools.xyz.
Inputs: text (required), locale.
Solve a triangle. mode=sss: three sides a,b,c. mode=sas: two sides a,b and the included angle angle_c (degrees). Returns sides, angles (degrees), area and perimeter. Runs on smart-tools.xyz.
Inputs: a (required), b (required), mode (required), c, +2 more.
Compare price per unit of two packs and report which is cheaper. Runs on smart-tools.xyz.
Inputs: price_a (required), price_b (required), quantity_a (required), quantity_b (required), +1 more.
Percent-encode or decode a URL. mode=component escapes /?&= (for a value); mode=full keeps them (for a whole address). Runs on smart-tools.xyz.
Inputs: text (required), mode, locale, direction.
Append encoded UTM campaign parameters to a URL, preserving any existing query and fragment. Runs on smart-tools.xyz.
Inputs: url (required), medium (required), source (required), campaign (required), +3 more.
Generate one or more random version 4 (RFC 4122) UUIDs. Runs on smart-tools.xyz.
Inputs: count, locale.
Add VAT to a net amount or remove it from a gross amount. Runs on smart-tools.xyz.
Inputs: rate (required), amount (required), locale, direction.
Convert a value between volume units. Units: m³ (Cubic meter), L (Liter), mL (Milliliter), gal_us (US gallon), gal_uk (UK gallon), qt (US quart), pt_us (US pint), pt_uk (UK pint), cup (US cup), fl oz (US fluid ounce). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
Compute the WCAG 2.x contrast ratio between two hex colors and whether it passes AA/AAA for normal and large text. Runs on smart-tools.xyz.
Inputs: background (required), foreground (required), locale.
Convert a value between weight units. Units: t (Tonne), kg (Kilogram), g (Gram), mg (Milligram), lb (Pound), oz (Ounce), st (Stone). Calculation runs on smart-tools.xyz.
Inputs: to (required), from (required), value (required), locale.
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69 free finance, military, school and everyday calculators as MCP tools.
500+ free tools over MCP: dev, text and security utilities, 230+ calculators. No sign-up.
Free calculators as MCP tools: finance, taxes, health, units, dates. Search, fetch & compute.
Over 200 free UK-focused calculators, converters and generators as MCP tools: take-home pay and National Insurance for 2026/27, VAT, stamp duty, mortgages, loans, savings, inflation since 1988, currency with live rates, dates and working days with bank holidays, unit conversions, health calculators, colour and text utilities, encoding, hashing, JWT and TOTP, and validators for IBANs and Bitcoin and Ethereum addresses. Every tool is read-only, stateless and computes on the spot; nothing you send is stored. Each result links to its source page on hopi.co.uk.
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