steps :

Identify the current farm patch level:
Central Admin – > Manage servers on this farm

Patch Level1.png

The configuration database version indicates the Build Number in the above example 15.0.4569.1000. You can also review the farm patch status by selecting the  Check product and patch installation status under Central Admin – > Upgrade and Migration – > Check product and patch installation status.

This page provide a more detailed view on the installed patches.

Patch Level2

Ok, so we have the build number what does it mean, it would have been nice if we had some meaningful information, like the date, so we can at least have an idea how late behind we are on our patches, or even a link to what the patch actually contains. In order to get this information you will need to compare the Build number to the table below:

Build Number Build Name Release Date Component Description
15.0.4919.1003 April 2017 CU 2017 April 11 SharePoint Foundation 2013 KB3178727
SharePoint Server 2013 KB3178730
Project Server 2013 KB3178728
15.0.4911.1001 March 2017 CU 2017 March 14 SharePoint Foundation 2013 KB3172456
SharePoint Server 2013 KB3172497
Project Server 2013 KB3172462
February 2017 CU N/A
15.0.4893.1001 January 2017 CU 2017 January 13 SharePoint Foundation 2013 KB3141479
SharePoint Server 2013 KB3141481
Project Server 2013 KB3141480
15.0.4885.1000 December 2016 CU 2016 December 13 SharePoint Foundation 2013 KB3128001
SharePoint Server 2013 KB3128005
Project Server 2013 KB3128003
15.0.4875.1000 November 2016 CU 2016 November 8 SharePoint Foundation 2013 KB3127930
SharePoint Server 2013 KB3127933
15.0.4875.1002 Project Server 2013 KB3127931
15.0.4867.1002 October 2016 CU 2016 October 11 SharePoint Foundation 2013 KB3118361
SharePoint Server 2013 KB3118366
15.0.4867.1003 Project Server 2013 KB3118365
15.0.4859.1000 September 2016 CU 2016 September 13 SharePoint Foundation 2013 KB3118271
SharePoint Server 2013 KB3118279
Project Server 2013 KB3118274
15.0.4849.1000 August 2016 CU 2016 August 9 SharePoint Foundation 2013 KB3115447
SharePoint Server 2013 KB3115450
15.0.4849.1002 Project Server 2013 KB3115448
15.0.4841.1000 July 2016 CU 2016 July 12 SharePoint Foundation 2013 KB3115290
SharePoint Server 2013 KB3115293
Project Server 2013 KB3115291
15.0.4833.1000 June 2016 CU 2016 June 14 SharePoint Foundation 2013 KB3115171
SharePoint Server 2013 KB3115174
Project Server 2013 KB3115172
15.0.4823.1003 May 2016 CU 2016 May 10 SharePoint Foundation 2013 KB3115023
SharePoint Server 2013 KB3115029
Project Server 2013 KB3115024
15.0.4815.1000 April 2016 CU 2016 April 12 SharePoint Foundation 2013 KB3114935
SharePoint Server 2013 KB3114938
Project Server 2013 KB3114936
15.0.4805.1000 March 2016 CU 2016 March 8 SharePoint Foundation 2013 KB3114822
SharePoint Server 2013 KB3114827
15.0.4805.1002 Project Server 2013 KB3114823
15.0.4797.1001 February 2016 CU 2016 February 9 SharePoint Foundation 2013 KB3114722
SharePoint Server 2013 KB3114726
Project Server 2013 KB3114723
15.0.4787.1000 January 2016 CU 2016 January 12 SharePoint Foundation 2013 KB3114492
SharePoint Server 2013 KB3114497
Project Server 2013 KB3114493
15.0.4779.1000 December 2015 CU 2015 December 8 SharePoint Foundation 2013 KB3114339
SharePoint Server 2013 KB3114345
Project Server 2013 KB3114341
15.0.4771.1000 November 2015 CU 2015 November 10 SharePoint Foundation 2013 KB3101368
SharePoint Server 2013 KB3101373
Project Server 2013 KB3101369
15.0.4763.1000 October 2015 CU 2015 October 13 SharePoint Foundation 2013 KB3085488
SharePoint Server 2013 KB3085492
Project Server 2013 KB3085489
15.0.4753.1000 September
2015 Updates
2015
September 8
SharePoint Foundation 2013 KB3085501
SharePoint Server 2013 KB3085481
KB3054998
KB3085483
KB3054870
KB3054813
Project Server 2013 KB3085505
15.0.4745.1000 August 2015 CU 2015 August 11 SharePoint Foundation 2013 KB3055004
SharePoint Server 2013 KB3055009
Project Server 2013 KB3055005
15.0.4737.1000 July 2015 CU 2015 July 14 SharePoint Foundation 2013 KB3054931
SharePoint Server 2013 KB3054937
15.0.4737.1001 Project Server 2013 KB3054933
15.0.4727.1001 June 2015 CU 2015 June 9 SharePoint Foundation 2013 KB3054864
SharePoint Server 2013 KB3054866
Project Server 2013 KB3054865
15.0.4719.1002 May 2015 CU 2015 May 12 SharePoint Foundation 2013 KB3039747
SharePoint Server 2013 KB3039780
Project Server 2013 KB3039753
15.0.4711.1000 April 2015 CU 2015 April 14 SharePoint Foundation 2013 KB2965261
SharePoint Server 2013 KB2965266
Project Server 2013 KB2965263
15.0.4701.1001 March 2015 CU 2015 March 10 SharePoint Foundation 2013 KB2956159
SharePoint Server 2013 KB2956166
Project Server 2013 KB2956162
15.0.4693.1001 February 2015 CU 2015 February 10 SharePoint Foundation 2013 KB2920801
SharePoint Server 2013 KB2920804
Project Server 2013 KB2920796
15.0.4675.1000 December 2014 CU 2014 December 9 SharePoint Foundation 2013 KB2910945
SharePoint Server 2013 KB2910938
Project Server 2013 KB2910911
15.0.4667.1000 November 2014 CU 2014 November 12 SharePoint Foundation 2013 KB2899468
SharePoint Server 2013 KB2889944
Project Server 2013 KB2889949
15.0.4659.1001 October 2014 Hotfix 2014 October 14 SharePoint Foundation 2013 KB2889946
SharePoint Server 2013 KB2899469
KB2880962
KB2880485
Project Server 2013 KB2889959
15.0.4649.1001 September 2014 CU 2014 September 9 SharePoint Foundation 2013 KB2883087
SharePoint Server 2013 KB2883068
Project Server 2013 KB2883072
15.0.4641.1001 August 2014 Hotfix 2014 August 12 SharePoint Foundation 2013 KB2883081
SharePoint Server 2013 KB2760213
KB2880559
KB2883078
KB2883085
KB2883086
Project Server 2013 KB2883083
15.0.4631.1001 July 2014 CU 2014 July 8 SharePoint Foundation 2013 KB2882999
SharePoint Server 2013 KB2882989
Project Server 2013 KB2882990
15.0.4617.1001 June 2014 CU 2014 June 10 SharePoint Foundation 2013 KB2881063
SharePoint Server 2013 KB2881061
Project Server 2013 KB2881062
15.0.4615.1001 MS14-022 2014 May 13 SharePoint Foundation 2013 KB2952166
SharePoint Server 2013 KB2952166
Project Server 2013 KB2952166
15.0.4605.1004 April 2014 CU 2014 May 7 SharePoint Foundation 2013 KB2863892
SharePoint Server 2013 KB2878240
Project Server 2013 KB2880484
15.0.4571.1502 Service Pack 1
(re-released)
2014 April 22 SharePoint Foundation 2013 KB2880551
SharePoint Server 2013 KB2880552
Project Server 2013 KB2880553
15.0.4569.1000
15.0.4569.1506
Service Pack 1
(replaced)
2014 February 25 SharePoint Foundation 2013 KB2817439
SharePoint Server 2013 KB2817429
Project Server 2013 KB2817434
15.0.4551.1508 December 2013 CU 2013 December 10 SharePoint Foundation 2013 KB2849961
15.0.4551.1511 SharePoint Server 2013 KB2850024
15.0.4551.1508 Project Server 2013 KB2837668
15.0.4551.1001 October 2013 CU 2013 October 8 SharePoint Foundation 2013 KB2825674
15.0.4551.1005 2013 October 26 SharePoint Server 2013 KB2825647
15.0.4551.1001 2013 October 8 Project Server 2013 KB2825659
15.0.4535.1000 August 2013 CU 2013 August 13 SharePoint Foundation 2013 KB2817517
SharePoint Server 2013 KB2817616
Project Server 2013 KB2817615
15.0.4517.1003 June 2013 CU 2013 June 26 SharePoint Foundation 2013 KB2817346
15.0.4517.1005 SharePoint Server 2013 KB2817414
Project Server 2013 KB2817415
15.0.4505.1002 April 2013 CU 2013 April 9 SharePoint Foundation 2013 KB2751999
15.0.4505.1005 2013 April 26 SharePoint Server 2013 KB2726992
Project Server 2013 KB2737990
15.0.4481.1005 March 2013 Public Update 2013 March 12 SharePoint Foundation 2013 KB2768000
SharePoint Server 2013 KB2767999
Project Server 2013 KB2768001
15.0.4433.1506 N/A N/A SharePoint Foundation 2013 N/A
December 2012 Hotfix 2013 December 11 SharePoint Server 2013 KB2752058
SharePoint Server 2013(coreserver) KB2752001
N/A N/A Project Server 2013 N/A
15.0.4420.1017 RTM 2012 October 24 SharePoint Foundation 2013 Download
SharePoint Server 2013 180-day trial
Project Server 2013 180-day trial
15.0.4481.1005 Beta 2012 July 18 SharePoint Foundation 2013
SharePoint Server 2013
Project Server 2013
Ref :
https://blogs.technet.microsoft.com/steve_chen/sharepoint-2013-build-numbers-and-cus/
https://technet.microsoft.com/en-us/library/mt715807(v=office.16).aspx
https://buildnumbers.wordpress.com/sharepoint/
https://support.microsoft.com/en-us/help/2880552/description-of-microsoft-sharepoint-server-2013-service-pack-1-sp1
https://blogs.technet.microsoft.com/stefan_gossner/2014/08/18/sharepoint-patching-demystified/

Base of my patch level and build number (marked in red) we now know that this farm is patched with SP1.

Identifying your current patches is the first step now we need to know which patches to install in order to bring your farm most updated patch level. Before we can do that we need to understand what the accumulative patches contains.