das heißt
/das ˈhaɪst/
"das heißt" is one of the most frequent connective phrases in German, used to clarify, rephrase, or draw a conclusion from a preceding statement. Depending on context and register, it corresponds to "that is", "i.e.", or "which means".
1. that is
Used to clarify or rephrase a statement without introducing a new logical consequence.
Er kommt morgen früh, das heißt, wir haben noch heute Abend Zeit.
He's arriving tomorrow morning, that is, we still have time tonight.
Der Vertrag gilt ab dem ersten, das heißt, du musst sofort handeln.
The contract takes effect on the first, that is, you need to act immediately.
2. i.e.
[formal]
The written, formal equivalent (mirrors the German abbreviation "d.h."); typical in reports, academic writing, and technical documents.
Die Regelung gilt für Minderjährige, das heißt, für alle unter 18 Jahren.
The regulation applies to minors, i.e., to everyone under the age of 18.
Wir suchen erfahrene Fachkräfte, das heißt, Bewerber mit mindestens fünf Jahren Berufserfahrung.
We are looking for experienced professionals, i.e., applicants with at least five years of relevant experience.
3. which means
Used when drawing a logical consequence or practical implication from what has just been stated.
Der Zug hat zwanzig Minuten Verspätung, das heißt, wir verpassen den Anschluss.
The train is twenty minutes late, which means we'll miss our connection.
Das Budget ist aufgebraucht, das heißt, neue Anschaffungen sind vorerst nicht möglich.
The budget has been exhausted, which means no new purchases are possible for now.
Notes
In written German, the phrase is routinely shortened to "d.h.", the direct counterpart to English "i.e." (Latin id est). Both typically follow a comma. When translating, match the register of the source: "that is" sounds more conversational, while "i.e." suits formal or academic contexts.