Other

Radioactive decay: remaining fraction after a time, time to reach a fraction (carbon dating), decay constant and mean life.

+7 more from Chemistry Calculators

Rail fence (zigzag) transposition cipher encode or decode with 2 to 20 rails; letters and digits only by default.

+7 more from Classic Ciphers and Encodings

Chi-square goodness of fit (observed vs expected counts) or independence test on a table, with p-value and effect size.

+8 more from Statistical Tests

Chance of a run: r successes in a row (or r identical outcomes) somewhere in n independent trials, like coin flips.

+7 more from Probability Calculators

Key signature (sharps or flats), circle-of-fifths neighbours, relative and parallel keys for any major or minor key.

+9 more from Music Theory

Required sample size for a survey (margin of error, optional finite population) or an A/B test (baseline, lift, power).

+8 more from Math and Statistics

Estimated maximum heart rate (Tanaka, Fox) and five training zones as percent of max or by heart-rate reserve (Karvonen).

+9 more from Fitness and Body Calculators

Posts, rails and pickets for a straight fence from its length, post spacing, picket width and gap.

+6 more from Construction Calculators

Engine RPM at a road speed (or speed at an RPM) from tire size, axle ratio and transmission gear ratios, with a table by gear.

+6 more from Automotive Calculators

ILLUSTRATIVE lime rate estimate to raise soil pH, by texture, product strength and depth. Not a lab recommendation.

+6 more from Farm & Garden Calc

Validate an SPDX license expression (AND, OR, WITH, +): syntax, known ids, known exceptions and deprecated identifiers.

+6 more from License Intel

Standard US trade book trim sizes in inches and mm, or look up one size like 6x9 and its closest standard.

+7 more from Publishing Calc

A number as English words: cardinal and ordinal, US or UK 'and' style, hyphenation, decimals, up to 36 digits.

+5 more from Number Words

R-value and U-factor of a wall or roof assembly from layers and thickness, with a framing-fraction correction and heat flow.

+7 more from Home Energy Calculators

Compare two packaged foods by barcode: Nutri-Score, NOVA, and per-100 g energy, sugars, saturated fat, salt, fibre and protein.

+6 more from Food Barcode Facts

2:3 pulldown cadence: which film frames land in which video fields and frames when 24 fps film is telecined.

+3 more from Video & Timecode Calc

Percent-encode or decode text as URL component, path, query or form data (UTF-8), with byte counts.

+4 more from URL & Text Tools

How many identical boxes fit inside a larger box or crate: best of six orientations in a simple grid, with utilization.

+6 more from Shipping & Logistics Calc

Signatures, press sheets and blank pages needed for a book of N pages at 4, 8, 16 or 32 pages per signature.

+5 more from Paper & Print Calc

Gear inches and speed at a cadence for every chainring and cog in a drivetrain, with the range, steps and duplicate gears.

+5 more from Bicycle Gearing & Fit Calc

Mixed-air temperature of two airstreams (return plus outside air) and the outside-air fraction.

+5 more from HVAC Airflow & Load Calc

Bandwidth of a VoIP call (IP and Ethernet level) for a codec and packetization time, and totals for many calls.

+7 more from Network Calc

65000 TRON energy for USDT (TRC-20) transfers, 1h rental, delivered to the TRON address in the quote. Pay in USDC on Base.

Generate, manage and explore your Switch AI image and video library, scoped to your account.

Read-only health context MCP server for Iris users.

Human for hire by AI agents: ground-truth checks, photo evidence, errands near Crystal Lake, IL

Air quality in St. Louis right now: European and US AQI, PM2.5, PM10, ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide with a health label, from Open-Meteo Air Quality (CAMS). Outdoor-activity and health decisions for St. Louis. $0.01 per call.

Everything free by Fergus Hume: the 100 catalogued public-domain books, audiobooks and texts credited to Fergus Hume across Project Gutenberg, LibriVox and Internet Archive, most popular first, each with direct download links. Add words to narrow by title. Re-verified daily. $0.01 per page of 20.

Is the IPv4 address inside 70.24.0.0/13 (Bell Canada)? Pure bit-mask check, no network call, returning inside true/false with the range's first/last address and size. Precise allow/deny rules for a well-known block. $0.01 per check.

Air quality in Milan right now: European and US AQI, PM2.5, PM10, ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide with a health label, from Open-Meteo Air Quality (CAMS). Outdoor-activity and health decisions for Milan. $0.01 per call.