mindestens
at least
Indicates a lower limit; not less than a certain number, amount, or measure.
Für diesen Job müssen Sie mindestens 25 Jahre alt sein.
For this job, you must be at least 25 years old.

at least
Loading your saved state.
at least
Indicates a lower limit; not less than a certain number, amount, or measure.
Für diesen Job müssen Sie mindestens 25 Jahre alt sein.
For this job, you must be at least 25 years old.

'Mindestens' (at least) is a superlative form derived from 'minder' (less). The ending '-stens' is used to form superlative adverbs and here expresses a lowest limit.
Die Reparatur wird mindestens eine Woche dauern.
The repair will take at least a week.
'Mindestens' (at least) often stands directly before the information it describes. However, it can also stand in position 1, in which case the verb follows directly after it (inversion).
Du solltest mindestens acht Stunden pro Nacht schlafen.
You should sleep at least eight hours per night.
In the meaning 'nicht weniger als' (not less than), 'mindestens' (at least) is almost always combined with numbers, amounts, or time expressions. Typical phrases are 'mindestens einmal' (at least once), 'mindestens drei Tage' (at least three days), or 'mindestens 10 Euro' (at least 10 euros).
Man muss mindestens 18 Jahre alt sein, um wählen zu dürfen.
You have to be at least 18 years old to be allowed to vote.
The meaning 'zumindest' (at least) is often recognized from the context of an expectation or reproach. The subjunctive II is frequently used here to describe an alternative, better action.
Du hättest mindestens eine Nachricht schreiben können, um Bescheid zu geben.
You could at least have written a message to let me know.
over / about
'über' and 'mindestens' can both be used with numbers and amounts, but they do not mean the same thing. 'über' means: more than a certain number. So the number mentioned itself is no longer included. 'mindestens' means: not less than this number. So the number mentioned is possible. Learners may confuse the words because both name a limit. The simple difference is: 'über 18' means 19 or more; 'mindestens 18' means 18 or more.

Für den Termin musst du mindestens zehn Minuten früher da sein.
For the appointment, you have to be there at least ten minutes early.
Der Eintritt kostet heute über zehn Euro.
Admission costs over ten euros today.