Units, currencies & weather
Convert 237 built-in units, 166 live fiat currencies, and look up the weather for a place you type.
Conversions are written as plain lines: 10 km to meter — in works just as
well (10 km in meter).
Unit conversions
The catalog holds 237 non-currency units covering length, area, volume, mass, time, speed, pressure, force, torque, energy, power, flow, viscosity, temperature and fuel economy, plus generated plural and SI-prefixed forms. Expressions may mix units:
20 km to meter 20,000 m
250 km to m 250,000 m
100 C° to F° 212 F°
34 C° to F° 93.2 F°
500 g to oz
Unit results keep their unit in the answer column, and unit-bearing values keep their unit when reused (see Variables & functions).
The Unit catalog lists every id, alias, SI prefix and dimension, and Units & quantities documents the whole syntax, including the phrase patterns:
90 km / 3 day 30 km/day
10 km in 45 min 0.2222 km/min
2.5 kg at €3 per kg €7.50
200 g of flour to ml 378.6 ml (≈)
Currency conversions
166 ISO 4217 fiat currency codes with live rates. All three spelling styles are accepted — codes, symbol forms and English names:
$500 to EUR
10 EUR to USD
$100 in EUR
10 Indian rupees to Japanese yen
Note: crypto assets and precious metals are not included — fiat only. Rates come from the free open.er-api.com service (no API key) and refresh hourly; the last good table keeps serving when you are offline.
The Currency reference lists every code, alias and marker.
Weather
Use any of the five strict, case-insensitive forms below. The first two return
the current temperature; high and low return today’s high and low; feels like
returns the current apparent temperature. Every result is in Celsius (shown as
C°):
weather in <place>
<place> temperature
high in <place>
low in <place>
feels like in <place>
The lookup goes to Open-Meteo with no key and no location permission — only the place you typed is ever sent; Numlex never accesses GPS or location. One last-good response per place supplies all four measurements, stays cached for 600 seconds and then refreshes in the background; offline the last reading remains available.
Geocoding-based place lookups and distance are documented in Live data & geography.
Offline behavior
All plain calculations, dates, variables, sections and unit conversions work fully offline. Currency and weather lines use their cached values until a fresh lookup is possible.
Where to go deeper
- Unit catalog — all 237 entries with a filter.
- Units & quantities — expressions, arithmetic, phrases and cooking densities.
- Currency reference — all 166 codes.
- Privacy & network — the exact network surface.