What is the batch size if we don't use optional scope parameters? | CRM Curator

200 records. That’s the default chunk size when you call Database.executeBatch(new MyBatch()) without the second argument.

Database.executeBatch(new MyBatch());            // chunks of 200
Database.executeBatch(new MyBatch(), 200);       // identical
Database.executeBatch(new MyBatch(), 50);        // chunks of 50

Why 200?

200 is also the trigger context size — when a trigger fires for a DML on 500 records, it runs three times, with 200 + 200 + 100 records each. Batch Apex matches that default so:

If you copy logic from a trigger into a batch’s execute, it works the same way without surprise governor limit changes.
Code tested at trigger-size scales also works in batch.

What 200 means for limits

Each execute runs in its own transaction with these per-transaction limits:

Limit	Value (async)
SOQL queries	100
Rows retrieved by SOQL	50,000
DML statements	150
DML rows	10,000
CPU time	60,000 ms
Heap	12 MB
Callouts	100

200 records is comfortably within these limits as long as your code is bulkified — i.e., one SOQL for the whole scope, one DML for the whole scope, not per record.

When 200 is too big

Scenario	What to do
Each record triggers a callout	Drop to 25–50 (100-callouts-per-transaction limit)
Each record causes a 5+ trigger cascade on related records	Drop to 50 or 25
Each record needs heavy CPU computation	Try 50; tune from there
You hit `Apex CPU time limit exceeded`	Halve the size, retest

When 200 is too small

Scenario	What to do
Pure field update, no triggers, no relations	Try 1,000
Mass delete of cold records	Try 500–2,000
Job takes too long (too many chunks)	Bigger scope = fewer transactions = less overall time

Practical recommendation

Start at 200. If anything fails — drop it. If everything’s fast and clean and you want to compress runtime — raise it. Don’t tune blindly; measure with actual data volume.

Common interview follow-ups

Can I change scope mid-job? — No, fixed at executeBatch time.
Is the chunk size visible to execute? — Yes, just count scope.size().
Does Iterable start use the same default? — Yes, 200.

Verified against: Apex Developer Guide — Using Batch Apex. Last reviewed 2026-05-17.