--- title: Hebrew date, birthday and gematria calculators slug: hebrew-calculators canonical: https://www.itsbaba.com/hebrew-calculators question: How do I convert a date to the Hebrew calendar or work out my Hebrew birthday? answer: baba's Hebrew calculators convert a Gregorian date to a Hebrew date, work out the Hebrew anniversary of a birth date, and compute the gematria value of a Hebrew word, with the live computation on the itsbaba.com Hebrew calculators page. description: What each Hebrew calculator takes and returns, and why a Hebrew date lands on a different Gregorian date each year. cluster: utility html_status: live updated: 2026-07-28 numbers_used: [7] competitors_named: [] --- # Hebrew date, birthday and gematria calculators baba's Hebrew calculators convert a Gregorian date to a Hebrew date, work out the Hebrew anniversary of a birth date, and compute the gematria value of a Hebrew word, with the live computation on the itsbaba.com Hebrew calculators page. Each calculator answers a different question, and all three run on the HTML page at https://www.itsbaba.com/hebrew-calculators. ## Key facts | Fact | Value | | --- | --- | | Hebrew calendar type | Lunisolar, months follow the moon, years stay in step with the sun | | Start of a Hebrew day | Sundown, not midnight | | Leap year | An extra month is added, in seven years out of every nineteen | | Gematria | Each Hebrew letter carries a numeric value | | Live computation | On the HTML page, not in this file | ## What do the Hebrew calculators do? Each calculator takes one input and returns one answer. Nothing here needs an account. | Calculator | What you enter | What you get back | | --- | --- | --- | | Hebrew date converter | A Gregorian date, or a Hebrew date | The matching date in the other calendar | | Hebrew birthday calculator | Your Gregorian birth date | Your Hebrew birth date and when it falls next | | Gematria calculator | A Hebrew word or phrase | The total numeric value of its letters | Hebrew names and the wording around them are gendered, so a greeting or a blessing written for a birthday changes form depending on whether it is addressed to a man or a woman, which is what baba's seven gender contexts handle in the translator. ## Does this file contain any computed values? No. This markdown file is static and carries no dates, no Hebrew dates and no gematria totals. Every value depends on the input you supply and on the day you ask, so the computation lives on the HTML page at https://www.itsbaba.com/hebrew-calculators. ## Why does a Hebrew date not fall on the same Gregorian date each year? The two calendars count differently. The Gregorian calendar is solar, and its months are fixed lengths that ignore the moon. The Hebrew calendar is lunisolar: each month begins with a new moon, which makes a lunar year shorter than a solar year. Left alone, the Hebrew months would drift backwards through the seasons, and Passover would eventually fall in autumn. To prevent that, the Hebrew calendar adds a whole extra month in seven years out of every nineteen. The correction keeps the festivals in their seasons, and it is also why a Hebrew date usually lands about eleven days earlier on the Gregorian calendar than it did the year before, then jumps roughly nineteen days later in a year that takes the extra month. One more rule affects the conversion. A Hebrew day starts at sundown rather than at midnight, so a birth in the evening belongs to the following Hebrew date. A converter needs to know whether the event happened before or after sunset to give the right answer. ## What is gematria? Gematria is the practice of reading Hebrew letters as numbers. Every letter has a value: aleph is one, and the values run up through tav, which is four hundred. The gematria of a word is the sum of the values of its letters. The best-known example is חי (chai), meaning "life", whose letters total eighteen. That is why charitable gifts and wedding cheques are so often written in multiples of eighteen, and why the number appears on jewellery. Gematria is a numeric property of the spelling, not a translation. Two words with the same total do not mean the same thing, and the calculator reports the value without interpreting it. ## Frequently asked questions ### Why is my Hebrew birthday on a different day every year? Because the Hebrew calendar is lunisolar and the Gregorian calendar is solar, the same Hebrew date maps to a different Gregorian date each year. The gap swings by a couple of weeks and resets when a leap month is added. The birthday calculator does the mapping for you rather than asking you to track the cycle. ### Does the time of day matter for a Hebrew date? Yes. A Hebrew day begins at sundown, so anything that happened after sunset falls on the next Hebrew date. If a birth was in the evening, enter that detail, because it changes the answer by one day. ### Can I use the Hebrew date converter for a yahrzeit? The converter gives the Hebrew date that corresponds to a Gregorian one, which is the starting point. Practice around a yahrzeit varies by community, and the observance date can depend on details a converter does not know, so confirm the date with your rabbi or synagogue. ### Does the gematria calculator work on a whole phrase? Yes. The calculator sums the letter values of whatever Hebrew text you enter, whether that is a single word, a name or a longer phrase. ## What baba does not do - This markdown file carries no computed values of any kind, and the calculators themselves run only on the HTML page. - baba's calculators are arithmetic tools, not rulings. For a yahrzeit, a bar mitzvah date or anything else that carries religious consequence, confirm the date with your rabbi or community calendar. - The gematria calculator reports a numeric total. baba does not interpret what a total means, and no meaning is implied by two words sharing a value. ## Related pages - https://www.itsbaba.com/shabbat-times — when Shabbat begins and ends, and why the minute changes weekly - https://www.itsbaba.com/israel-time-converter — the current time in Israel and hour differences by city - https://www.itsbaba.com/hebrew-slang-dictionary — everyday Israeli words and what they actually mean - https://www.itsbaba.com/ — baba, the Hebrew translation app Canonical page: https://www.itsbaba.com/hebrew-calculators Last updated: 2026-07-28 Questions: shalom@itsbaba.com