Short title

S3 Multipart Upload & Part Size Calculator

Calculate optimal AWS S3 multipart upload part sizes, part counts, memory buffers, transfer duration, and PUT costs while enforcing S3 hard architectural limits.

Lbl presets
Lbl config card
10 Lbl threads
Lbl thread minLbl aws cli defaultLbl thread max
0.2%
Lbl direct connectLbl typical wanLbl lossy cellular
Unit mib
Lbl compliance card
Part Size ≥ 5 MiB Floor
Lbl passed

Every part except the last must be at least 5 MiB (5,242,880 bytes).

Lbl current value64.0 MiB
Part Size ≤ 5 GiB Ceiling
Lbl passed

No single part may exceed 5 GiB (5,368,709,120 bytes).

Lbl current value64.0 MiB
Part Count ≤ 10,000 Parts
Lbl passed

An S3 object cannot have more than 10,000 parts.

Lbl current value1,600 / 10,000
Object Size ≤ 5 TiB Maximum
Lbl passed

Total object size cannot exceed 5 TiB (5,497,558,138,880 bytes).

Lbl current value100 GiB
Buffer Memory Within Host RAM
Lbl passed

Peak in-flight RAM consumption must not exceed specified container RAM budget.

Lbl current value640 MiB (31.3%)
Lbl primary metrics
Lbl optimal part size
64.0 MiB

67,108,864 Lbl bytes

Lbl total parts count
1,600

16.0% Lbl of max quota

Lbl final part size
64.0 MiB

67,108,864 Lbl bytes

Lbl in flight ram
640 MiB

31.3% Lbl of host ram

Lbl est transfer time
28m 52s

Lbl effective 996.0 Mbps

Lbl total api cost
$0.016 USD

3,202 Lbl api calls

Desc sensitivity

Th candidate part sizeTh parts countTh s3 validityTh peak ramTh retry penaltyTh api costTh verdict
5.00 MiB20,480TooManyParts (> 10k)50.0 MiB1s$0.205 USDViolates 10k Cap
8.00 MiB12,800TooManyParts (> 10k)80.0 MiB1s$0.128 USDViolates 10k Cap
16.0 MiB6,400Valid Spec160 MiB1s$0.064 USDHigh API Calls
32.0 MiB3,200Valid Spec320 MiB1s$0.032 USDViable Option
64.0 MiB1,600Valid Spec640 MiB1s$0.016 USD★ Selected
128 MiB800Valid Spec1.25 GiB2s$0.0080 USDViable Option
256 MiB400Valid Spec2.50 GiB3s$0.0040 USDOOM Crash Risk
512 MiB200Valid Spec5.00 GiB5s$0.0020 USDOOM Crash Risk
1.00 GiB100Valid Spec10.0 GiB9s$0.0010 USDOOM Crash Risk
5.00 GiB20Valid Spec50.0 GiB44s$0.0002 USDOOM Crash Risk
Lbl active parts stat1,600
Lbl part floor stat64.0 MiB
Lbl ram saturation stat31.3%
Lbl effective speed stat996.0 Mbps
Lbl retransmit stat100 GiB
Lbl total requests stat3,202