NOAA CO-OPS station facts: name, state, coordinates, time zone, tidal or Great Lakes, and station type.

Latitude/longitude and EPSG:3857 metre bounds of a slippy-map tile x/y/z, with its centre and ground size.

Zoom-level ladder 0 to 24: tiles per side, metres per pixel, map scale and typical use, at a chosen latitude.

Latest observed water level at a NOAA station against its tide prediction: the difference shows surge or blow-out in feet.

Beaufort wind force and Douglas sea state from a wind speed and wave height, with plain-language descriptions of sea conditions.

Upcoming high and low tides at a NOAA tide station: UTC and local times, heights in feet above MLLW, next tide and tidal range.

Highest map zoom level at which a lat/lon bounding box fits a viewport of given pixel size, with centre and tile span.

Latest NDBC buoy observation: wind, gust, waves, swell, pressure and water temperature, with a Beaufort and sea-state screen.

The nearest active NOAA/NDBC buoys and stations that report weather, with distance, owner and type.

The nearest NOAA tide-prediction stations to a latitude and longitude, with distance in km and miles.

Aquarium volume in US gallons and litres from inside dimensions, usable water after substrate, and the water's weight.

Pixels needed for a print size at a dpi (with bleed), or the largest print size an image supports at a chosen dpi.

Which standard envelopes (#10, A2, A7, C5, DL, C6 and more) hold a card or folded sheet, with the margin left over.

ISO 216 size in mm, inches and points for A0-A10, B0-B10, C0-C10, with area, aspect ratio and the neighbouring sizes.

Convert paper gsm to US basis weight (bond, text, cover) and weigh a sheet, a ream or a mailing from its size.

Convert between points, picas, inches, mm, cm, CSS pixels, TeX points, Didot and twips, and show the pica-and-points form.

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

How many cards, labels or small sheets fit on a large sheet in a grid, trying both rotations, with margin, gutter and waste.

Letter, Legal, Tabloid, ANSI A-E and Architectural A-E paper sizes in inches, mm and points, with the closest ISO size.

Human-equivalent age of a dog by the AVMA 15-9-5 rule and the 2020 epigenetic-clock formula 16 ln(age) + 31.