diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4fe0d6192..686794c1b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   to compare two AXI buses on an FPGA.
 - Add `axi_lite_from_mem` and `axi_from_mem` acting like SRAMs making AXI4 requests downstream.
 - Add `axi_rw_join` and `axi_rw_split` to split/join AXI buses.
+- Add `#_width` functions returning the width of the AXI channels.
 
 ### Changed
 - `axi_demux`: Replace FIFO between AW and W channel by a register plus a counter.  This prevents
@@ -21,6 +22,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - `axi_xbar`: Add parameter `PipelineStages` to `axi_pkg::xbar_cfg_t`.  This adds `axi_multicuts`
   in the crossed connections in the xbar between the demuxes and muxes.
 - `axi_pkg`: Add documentation to `xbar_cfg_t`.
+- `axi_pkg`: Define `localparams` to define AXI type widths.
 
 ### Fixed
 
diff --git a/src/axi_pkg.sv b/src/axi_pkg.sv
index 7ef3bbcd7..583846491 100644
--- a/src/axi_pkg.sv
+++ b/src/axi_pkg.sv
@@ -19,26 +19,49 @@
 //! AXI Package
 /// Contains all necessary type definitions, constants, and generally useful functions.
 package axi_pkg;
-  /// AXI Transaction Burst Type.
-  typedef logic [1:0] burst_t;
+    /// AXI Transaction Burst Width.
+  parameter int unsigned BurstWidth  = 32'd2;
+  /// AXI Transaction Response Width.
+  parameter int unsigned RespWidth   = 32'd2;
+  /// AXI Transaction Cacheability Width.
+  parameter int unsigned CacheWidth  = 32'd4;
+  /// AXI Transaction Protection Width.
+  parameter int unsigned ProtWidth   = 32'd3;
+  /// AXI Transaction Quality of Service Width.
+  parameter int unsigned QosWidth    = 32'd4;
+  /// AXI Transaction Region Width.
+  parameter int unsigned RegionWidth = 32'd4;
+  /// AXI Transaction Length Width.
+  parameter int unsigned LenWidth    = 32'd8;
+  /// AXI Transaction Size Width.
+  parameter int unsigned SizeWidth   = 32'd3;
+  /// AXI Lock Width.
+  parameter int unsigned LockWidth   = 32'd1;
+  /// AXI5 Atomic Operation Width.
+  parameter int unsigned AtopWidth   = 32'd6;
+  /// AXI5 Non-Secure Address Identifier.
+  parameter int unsigned NsaidWidth  = 32'd4;
+
+  /// AXI Transaction Burst Width.
+  typedef logic [BurstWidth-1:0]  burst_t;
   /// AXI Transaction Response Type.
-  typedef logic [1:0] resp_t;
+  typedef logic [RespWidth-1:0]   resp_t;
   /// AXI Transaction Cacheability Type.
-  typedef logic [3:0] cache_t;
+  typedef logic [CacheWidth-1:0]  cache_t;
   /// AXI Transaction Protection Type.
-  typedef logic [2:0] prot_t;
+  typedef logic [ProtWidth-1:0]   prot_t;
   /// AXI Transaction Quality of Service Type.
-  typedef logic [3:0] qos_t;
+  typedef logic [QosWidth-1:0]    qos_t;
   /// AXI Transaction Region Type.
-  typedef logic [3:0] region_t;
+  typedef logic [RegionWidth-1:0] region_t;
   /// AXI Transaction Length Type.
-  typedef logic [7:0] len_t;
+  typedef logic [LenWidth-1:0]    len_t;
   /// AXI Transaction Size Type.
-  typedef logic [2:0] size_t;
+  typedef logic [SizeWidth-1:0]   size_t;
   /// AXI5 Atomic Operation Type.
-  typedef logic [5:0] atop_t; // atomic operations
+  typedef logic [AtopWidth-1:0]   atop_t; // atomic operations
   /// AXI5 Non-Secure Address Identifier.
-  typedef logic [3:0] nsaid_t;
+  typedef logic [NsaidWidth-1:0]  nsaid_t;
 
   /// In a fixed burst:
   /// - The address is the same for every transfer in the burst.
@@ -290,6 +313,65 @@ package axi_pkg;
     endcase
   endfunction
 
+  /// AW Width: Returns the width of the AW channel payload
+  function automatic int unsigned aw_width(int unsigned addr_width, int unsigned id_width,
+                                           int unsigned user_width );
+    // Sum the individual bit widths of the signals
+    return (id_width + addr_width + LenWidth + SizeWidth + BurstWidth + LockWidth + CacheWidth +
+            ProtWidth + QosWidth + RegionWidth + AtopWidth + user_width );
+  endfunction
+
+  /// W Width: Returns the width of the W channel payload
+  function automatic int unsigned w_width(int unsigned data_width, int unsigned user_width );
+    // Sum the individual bit widths of the signals
+    return (data_width + data_width / 32'd8 + 32'd1 + user_width);
+    //                   ^- StrobeWidth       ^- LastWidth
+  endfunction
+
+  /// B Width: Returns the width of the B channel payload
+  function automatic int unsigned b_width(int unsigned id_width, int unsigned user_width );
+    // Sum the individual bit widths of the signals
+    return (id_width + RespWidth + user_width);
+  endfunction
+
+  /// AR Width: Returns the width of the AR channel payload
+  function automatic int unsigned ar_width(int unsigned addr_width, int unsigned id_width,
+                                           int unsigned user_width );
+    // Sum the individual bit widths of the signals
+    return (id_width + addr_width + LenWidth + SizeWidth + BurstWidth + LockWidth + CacheWidth +
+            ProtWidth + QosWidth + RegionWidth + user_width );
+  endfunction
+
+  /// R Width: Returns the width of the R channel payload
+  function automatic int unsigned r_width(int unsigned data_width, int unsigned id_width,
+                                          int unsigned user_width );
+    // Sum the individual bit widths of the signals
+    return (id_width + data_width + RespWidth + 32'd1 + user_width);
+    //                                          ^- LastWidth
+  endfunction
+
+  /// Request Width: Returns the width of the request channel
+  function automatic int unsigned req_width(int unsigned addr_width,    int unsigned data_width,
+                                            int unsigned id_width,      int unsigned aw_user_width,
+                                            int unsigned ar_user_width, int unsigned w_user_width   );
+    // Sum the individual bit widths of the signals and their handshakes
+    //                                                      v- valids
+    return (aw_width(addr_width, id_width, aw_user_width) + 32'd1 +
+            w_width(data_width, w_user_width)             + 32'd1 +
+            ar_width(addr_width, id_width, ar_user_width) + 32'd1 + 32'd1 + 32'd1 );
+    //                                                              ^- R,   ^- B ready
+  endfunction
+
+  /// Response Width: Returns the width of the response channel
+  function automatic int unsigned rsp_width(int unsigned data_width,   int unsigned id_width,
+                                            int unsigned r_user_width, int unsigned b_user_width );
+    // Sum the individual bit widths of the signals and their handshakes
+    //                                                    v- valids
+    return (r_width(data_width, id_width, r_user_width) + 32'd1 +
+            b_width(id_width, b_user_width)             + 32'd1 + 32'd1 + 32'd1 + 32'd1);
+    //                                                            ^- AW,  ^- AR,  ^- W ready
+  endfunction
+
   // ATOP[5:0]
   /// - Sends a single data value with an address.
   /// - The target swaps the value at the addressed location with the data value that is supplied in
@@ -447,4 +529,5 @@ package axi_pkg;
     logic [31:0] start_addr;
     logic [31:0] end_addr;
   } xbar_rule_32_t;
+
 endpackage