diff --git a/manual/manual-3.tex b/manual/manual-3.tex
index 2044b53..dc7be7a 100644
--- a/manual/manual-3.tex
+++ b/manual/manual-3.tex
@@ -46,6 +46,7 @@ \section{Inner specifications}
   \K{leftsep} & set horizontal space to the left of every column & \V{6pt} \\
   \K{rightsep} & set horizontal space to the right of every column & \V{6pt} \\
   \K{colsep} & set horizontal space to both sides of every column & \V{6pt} \\
+  \K{spread} & extendable column spread algorithm: \V{default}, \V{coeff}, or \V{none} & \V{default} \\
   \K{hspan} & horizontal span algorithm: \V{default}, \V{even}, or \V{minimal} & \V{default} \\
   \K{vspan} & vertical span algorithm: \V{default} or \V{even} & \V{default} \\
   %\K{verb} & you need this key to use verb commands & \None \\
@@ -166,6 +167,48 @@ \subsection{Hspan and vspan algorithms}
 \end{tblr}
 \end{demohigh}
 
+\subsection{Spread algorithms for extendable columns}
+
+The algorithm specified by the \K{spread} key applies only
+if all of the following are true:
+\begin{itemize}
+  \item There is at least one extendable column (\V{X} column).
+  \item All extendable columns have negative coefficients.
+  \item The total natural width of \emph{all} columns
+    (including column separations and vlines) is less than the specified
+    width of the table (or \CC{\linewidth} if no \K{width} is specified).
+\end{itemize}
+
+With \KV{spread=default}, the remaining width is distributed
+among the extendable columns according to their natural widths:
+\begin{demohigh}
+\SetTblrInner{hlines, vlines, spread=default}
+\begin{tblr}{colspec={*{3}{X[-1]}}}
+ Short & Medium-sized & Long extendable column test 123
+\end{tblr}
+\end{demohigh}
+
+With \KV{spread=coeff}, the remaining width is distributed
+among the extendable columns according to their coefficients:
+\begin{demohigh}
+\SetTblrInner{hlines, vlines, spread=coeff}
+\begin{tblr}{colspec={*{3}{X[-1]}}}
+ Short & Medium-sized & Long extendable column test 123
+\end{tblr}
+\begin{tblr}{colspec={X[-1]X[-1]X[-2]}}
+ Short & Medium-sized & Long extendable column test 123
+\end{tblr}
+\end{demohigh}
+
+With \KV{spread=none}, the width of the table is reduced
+to match the natural column widths:
+\begin{demohigh}
+\SetTblrInner{hlines, vlines, spread=none}
+\begin{tblr}{colspec={*{3}{X[-1]}}}
+ Short & Medium-sized & Long extendable column test 123
+\end{tblr}
+\end{demohigh}
+
 \subsection{Set baseline for the table}
 
 With \K{baseline} key, you can set baseline for the table.
diff --git a/tabularray.sty b/tabularray.sty
index 41c2854..ad5094f 100644
--- a/tabularray.sty
+++ b/tabularray.sty
@@ -4005,6 +4005,7 @@
     hspan .code:n = \__tblr_keys_gput:nn { hspan } {#1},
     vspan .code:n = \__tblr_keys_gput:nn { vspan } {#1},
     stretch .code:n = \__tblr_keys_gput:nn { stretch } {#1},
+    spread .code:n = \__tblr_keys_gput:nn { spread } {#1},
     columns .code:n = \__tblr_set_every_column_aux:n {#1},
     rows    .code:n = \__tblr_set_every_row_aux:n {#1},
     cells   .code:n = \__tblr_set_every_cell_aux:n {#1},
@@ -4969,6 +4970,7 @@
 
 \dim_new:N \l__tblr_column_target_dim
 \prop_new:N \l__tblr_column_coefficient_prop
+\prop_new:N \l__tblr_column_n_coefficient_prop
 \prop_new:N \l__tblr_column_natural_width_prop
 \prop_new:N \l__tblr_column_computed_width_prop
 
@@ -4999,6 +5001,7 @@
       { \dim_set_eq:NN \l__tblr_column_target_dim \linewidth }
       { \dim_set:Nn \l__tblr_column_target_dim { \l_tmpa_tl } }
     \prop_clear:N \l__tblr_column_coefficient_prop
+    \prop_clear:N \l__tblr_column_n_coefficient_prop
     \prop_clear:N \l__tblr_column_natural_width_prop
     \prop_clear:N \l__tblr_column_computed_width_prop
     \int_step_variable:nNn { \c@colcount } \l__tblr_j_tl
@@ -5061,7 +5064,12 @@
       { \dim_compare_p:nNn { \l__tblr_column_target_dim } > { \l__tblr_hfuzz_dim } }
       {
         \prop_if_empty:NTF \l__tblr_column_coefficient_prop
-          { \__tblr_adjust_extendable_column_width_negative: }
+          {
+            \str_if_eq:enTF
+              { \__tblr_prop_item:ne { inner } { spread } } { none }
+                { \dim_zero:N \l__tblr_column_target_dim }
+                { \__tblr_adjust_extendable_column_width_negative: }
+          }
           { \__tblr_adjust_extendable_column_width_once: }
       }
     \prop_map_inline:Nn \l__tblr_column_computed_width_prop
@@ -5112,6 +5120,7 @@
                 \dim_add:Nn \l__tblr_column_target_dim
                   { \l__tblr_a_tl + \l__tblr_c_tl - \l__tblr_b_tl }
                 \prop_remove:Nn \l__tblr_column_coefficient_prop { ##1 }
+                \prop_put:Nne \l__tblr_column_n_coefficient_prop { ##1 } { ##2 }
               }
               {
                 \__tblr_add_dimen_value:Nnn
@@ -5123,6 +5132,15 @@
   }
 
 \cs_new_protected:Npn \__tblr_adjust_extendable_column_width_negative:
+  {
+    \str_if_eq:enTF
+      { \__tblr_prop_item:ne { inner } { spread } } { coeff }
+        { \__tblr_adjust_extendable_column_width_coeff: }
+        { \__tblr_adjust_extendable_column_width_natural: }
+    \LogTblrTracing { target }
+  }
+
+\cs_new_protected:Npn \__tblr_adjust_extendable_column_width_natural:
   {
     \dim_zero:N \l_tmpa_dim
     \prop_map_inline:Nn \l__tblr_column_natural_width_prop
@@ -5136,7 +5154,25 @@
         \__tblr_add_dimen_value:Nnn
           \l__tblr_column_computed_width_prop { ##1 } { \l_tmpb_tl }
       }
-    \LogTblrTracing { target }
+  }
+
+\cs_new_protected:Npn \__tblr_adjust_extendable_column_width_coeff:
+  {
+    \dim_zero:N \l_tmpa_dim
+    \prop_map_inline:Nn \l__tblr_column_n_coefficient_prop
+      {
+        \dim_add:Nn \l_tmpa_dim { \dim_abs:n { ##2 pt } }
+      }
+    \tl_set:Ne \l__tblr_w_tl
+      { \dim_ratio:nn { \l__tblr_column_target_dim } { \l_tmpa_dim } }
+    \dim_zero:N \l__tblr_column_target_dim
+    \prop_map_inline:Nn \l__tblr_column_n_coefficient_prop
+      {
+        \tl_set:Ne \l__tblr_a_tl
+          { \dim_eval:n { \dim_abs:n { ##2 pt } * \l__tblr_w_tl } }
+        \__tblr_add_dimen_value:Nnn
+          \l__tblr_column_computed_width_prop { ##1 } { \l__tblr_a_tl }
+      }
   }
 
 %%% --------------------------------------------------------
diff --git a/tabularray.tex b/tabularray.tex
index e5aa9d4..94bb1a2 100644
--- a/tabularray.tex
+++ b/tabularray.tex
@@ -1440,6 +1440,7 @@ \section{Inner specifications}
   \K{leftsep} & set horizontal space to the left of every column & \V{6pt} \\
   \K{rightsep} & set horizontal space to the right of every column & \V{6pt} \\
   \K{colsep} & set horizontal space to both sides of every column & \V{6pt} \\
+  \K{spread} & extendable column spread algorithm: \V{default}, \V{coeff}, or \V{none} & \V{default} \\
   \K{hspan} & horizontal span algorithm: \V{default}, \V{even}, or \V{minimal} & \V{default} \\
   \K{vspan} & vertical span algorithm: \V{default} or \V{even} & \V{default} \\
   %\K{verb} & you need this key to use verb commands & \None \\
@@ -1560,6 +1561,48 @@ \subsection{Hspan and vspan algorithms}
 \end{tblr}
 \end{demohigh}
 
+\subsection{Spread algorithms for extendable columns}
+
+The algorithm specified by the \K{spread} key applies only
+if all of the following are true:
+\begin{itemize}
+  \item There is at least one extendable column (\V{X} column).
+  \item All extendable columns have negative coefficients.
+  \item The total natural width of \emph{all} columns
+    (including column separations and vlines) is less than the specified
+    width of the table (or \CC{\linewidth} if no \K{width} is specified).
+\end{itemize}
+
+With \KV{spread=default}, the remaining width is distributed
+among the extendable columns according to their natural widths:
+\begin{demohigh}
+\SetTblrInner{hlines, vlines, spread=default}
+\begin{tblr}{colspec={*{3}{X[-1]}}}
+ Short & Medium-sized & Long extendable column test 123
+\end{tblr}
+\end{demohigh}
+
+With \KV{spread=coeff}, the remaining width is distributed
+among the extendable columns according to their coefficients:
+\begin{demohigh}
+\SetTblrInner{hlines, vlines, spread=coeff}
+\begin{tblr}{colspec={*{3}{X[-1]}}}
+ Short & Medium-sized & Long extendable column test 123
+\end{tblr}
+\begin{tblr}{colspec={X[-1]X[-1]X[-2]}}
+ Short & Medium-sized & Long extendable column test 123
+\end{tblr}
+\end{demohigh}
+
+With \KV{spread=none}, the width of the table is reduced
+to match the natural column widths:
+\begin{demohigh}
+\SetTblrInner{hlines, vlines, spread=none}
+\begin{tblr}{colspec={*{3}{X[-1]}}}
+ Short & Medium-sized & Long extendable column test 123
+\end{tblr}
+\end{demohigh}
+
 \subsection{Set baseline for the table}
 
 With \K{baseline} key, you can set baseline for the table.