Tools
Exact answers,
quickly.
The small things you look up two or three times a year and never remember where to find.
Hebrew date converter
לוּחַAny civil date to its Hebrew date. Remember that the Hebrew date starts the evening before.
Bar mitzvah, birthday and yahrzeit
יוֹם הַשָּׁנָהFrom a civil date of birth: the Hebrew birthday at 1, 5, 12, 13, 18 and 20 years — with the parsha for each.
Gematria
גִּימַטְרִיָּאStandard, gadol, katan and ordinal, with the working shown.
Standard
18
Gadol
18
Katan
9
Ordinal
18
ח8י10
As Hebrew numerals: יח
Which way is Jerusalem
מִזְרָחThe great-circle bearing to the Kosel, with a live compass where your phone has one.
287°
WNW — the great-circle bearing to the Kosel
14,135 km away
This is the shortest path over the globe, not “face east”. From Australia the two differ by about sixty degrees — the great circle to Jerusalem runs well north of west. Most Australian shuls are built this way; where yours differs, daven with your shul.
The ten sefiros
סְפִירוֹתThe names behind the Omer count — tap one.
Keser
כֶּֽתֶר
crown
The lower seven are the ones counted through the Omer — a week each, and a day each within the week. The count for today is on Today through Sefirah.
Shiurim
שִׁעוּרִיםRevi'is, kezayis, tefach, amah and mil — both opinions, side by side.
| Measure | R' Chaim Naeh | Chazon Ish |
|---|---|---|
| Revi'isרְבִיעִיתKiddush, havdalah, the four cups, and the minimum for a bracha acharona on a drink. | 86 ml | 150 ml |
| KezayisכְּזַיִתMatzah, maror, and the minimum for bentching. Widely discussed — many hold by a range between these. | 28.8 ml | 50 ml |
| KebeitzaכְּבֵיצָהTwo kezaysim. Relevant to washing for bread and to tumah shiurim. | 57.6 ml | 100 ml |
| TefachטֶפַחA handbreadth. Sukkah walls, mechitza heights, and much of hilchos Shabbos. | 8 cm | 9.6 cm |
| AmahאַמָּהSix tefachim. Sukkah minimum and maximum heights, techum boundaries. | 48 cm | 57.6 cm |
| Milמִיל2,000 amos. Used for techum Shabbos and for the time-based shiurim of a mil's walk. | 960 m | 1152 m |
Both columns are given because the difference between them is the answer — this is the one tool here where the result is an opinion rather than a calculation. Figures are the commonly cited ones. Which you use, and when, is a question for your rav.
These are aids, not psak. Where a date, a measure or a direction actually matters — a yahrzeit, a get, a sukkah wall — check it with your rav. And see the luach for zmanim.