diff --git a/CHANGELOG.md b/CHANGELOG.md
index d5614bb56..3b99f0d44 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 - Renamed variable in pipeline.finalise to better reflect what the dataframe represents (sources_df -> associations_df) [#787](https://github.com/askap-vast/vast-pipeline/pull/787)
 - Fixed typo in variable name ("assoications") [#787](https://github.com/askap-vast/vast-pipeline/pull/787)
+- Fix partition calculation from wrong DataFrame object [#783](https://github.com/askap-vast/vast-pipeline/pull/783)
 - Fix processing config parameters not displaying in web interface [#782](https://github.com/askap-vast/vast-pipeline/pull/782)
 - Fix incorrect zenodo links [#780](https://github.com/askap-vast/vast-pipeline/pull/780)
 
@@ -30,6 +31,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 - [#788](https://github.com/askap-vast/vast-pipeline/pull/788): feat, fix: Speed up forced fitting code by using numba-fied forced_phot code and reordering some calculations
 - [#787](https://github.com/askap-vast/vast-pipeline/pull/787): fix: Optimise associations merge and minor variable name updates
+- [#783](https://github.com/askap-vast/vast-pipeline/pull/783): fix: Fix partition calculation from wrong DataFrame object
 - [#782](https://github.com/askap-vast/vast-pipeline/pull/782): fix: Fix processing config parameters not displaying in web interface
 - [#780](https://github.com/askap-vast/vast-pipeline/pull/780): docs: Fix incorrect zenodo links
 
diff --git a/vast_pipeline/pipeline/new_sources.py b/vast_pipeline/pipeline/new_sources.py
index 4ef9dd08a..23879a650 100644
--- a/vast_pipeline/pipeline/new_sources.py
+++ b/vast_pipeline/pipeline/new_sources.py
@@ -236,7 +236,7 @@ def parallel_get_rms_measurements(
     }
 
     n_workers, n_partitions = calculate_workers_and_partitions(
-        df,
+        out,
         n_cpu=n_cpu,
         max_partition_mb=max_partition_mb
     )
diff --git a/vast_pipeline/pipeline/pairs.py b/vast_pipeline/pipeline/pairs.py
index 8d678cc11..2ca17c17c 100644
--- a/vast_pipeline/pipeline/pairs.py
+++ b/vast_pipeline/pipeline/pairs.py
@@ -72,7 +72,7 @@ def calculate_measurement_pair_metrics(
     """
     
     n_workers, n_partitions = calculate_workers_and_partitions(
-        df,
+        df.set_index('source'),
         n_cpu=n_cpu,
         max_partition_mb=max_partition_mb
     )
diff --git a/vast_pipeline/utils/utils.py b/vast_pipeline/utils/utils.py
index a57dd0c74..e06e95029 100644
--- a/vast_pipeline/utils/utils.py
+++ b/vast_pipeline/utils/utils.py
@@ -422,7 +422,7 @@ def calculate_n_partitions(df, n_cpu, partition_size_mb=15):
 
     partition_size_mb = int(np.ceil(mem_usage_mb / n_partitions))
 
-    logger.debug("Using %d partions of %dMB", n_partitions, partition_size_mb)
+    logger.debug("Using %d partitions of %dMB", n_partitions, partition_size_mb)
 
     return n_partitions