Country for an ITU E.164 calling code or international number prefix, such as +44 or +1 876; flags shared codes.

Languages listed for a country with ISO 639-1 and 639-2 codes and names, from a country name or ISO code.

Stair layout from total rise: number of risers, exact riser height, total run, stringer length, angle and a code check.

US state, DC and territory lookup by USPS postal code, name or FIPS number; returns all three plus the type.

gcd, lcm and extended-Euclid Bezout coefficients of two integers, plus gcd/lcm of up to 20 more.

Look up a language by ISO 639-1, 639-2 (B or T) code, BCP 47 tag or English name; returns all code forms.

ISO 4217 currency details by code, number or name: minor units, issuers, countries; optional exact rounding of an amount.

Normalise country names like USA, U.S. or United States of America to ISO codes; up to 25 per call, with confidence.

Tiles needed for a floor or wall from area or room size, tile size, grout gap and waste, plus boxes if you give tiles per box.

Validate an ISO 3166-1, 4217 or 639 code or a ccTLD or dial code: assigned, reserved, deleted or unknown.

Currency of a country (code, number, minor units) or every country using a currency, by ISO 4217.

Convert an ISO 3166-1 country code between alpha-2, alpha-3 and numeric; also name, currency, ccTLD, calling code.

Solve x = a1 (mod m1), x = a2 (mod m2), ... with the Chinese remainder theorem, coprime or not.

Look up a country, currency or language from any ISO code, TLD or name, with fuzzy matching and ambiguity flags.

Generate or validate Luhn and ISO 7064 mod 97-10 (IBAN style) check digits from the string you supply.

SLA availability (99.9 percent, three nines) to allowed downtime per day, month and year; series and parallel composition.

Requests per second times payload size to Mbps with peak factor, protocol overhead and link headroom; or IOPS to MB/s.

Modular exponentiation base^exp mod m for big integers, decimal or 0x hex, up to 4096 bits.

RAID 0/1/5/6/10 and ZFS RAID-Z usable capacity, efficiency, fault tolerance, write penalty and rebuild read-error risk.

M/M/1 and M/M/c queue: utilisation, probability of waiting (Erlang C), queue length, wait and response time, tail odds.