diff --git a/format.c b/format.c
index 03fcce5c..dd3af400 100644
--- a/format.c
+++ b/format.c
@@ -1984,7 +1984,17 @@ format_replace_expression(struct format_modifier *mexp,
 	int			 use_fp = 0;
 	u_int			 prec = 0;
 	double			 mleft, mright, result;
-	enum { ADD, SUBTRACT, MULTIPLY, DIVIDE, MODULUS } operator;
+	enum { ADD,
+	       SUBTRACT,
+	       MULTIPLY,
+	       DIVIDE,
+	       MODULUS,
+	       EQUAL,
+	       NOT_EQUAL,
+	       GREATER_THAN,
+	       GREATER_THAN_EQUAL,
+	       LESS_THAN,
+	       LESS_THAN_EQUAL } operator;
 
 	if (strcmp(mexp->argv[0], "+") == 0)
 		operator = ADD;
@@ -1997,6 +2007,18 @@ format_replace_expression(struct format_modifier *mexp,
 	else if (strcmp(mexp->argv[0], "%") == 0 ||
 	    strcmp(mexp->argv[0], "m") == 0)
 		operator = MODULUS;
+	else if (strcmp(mexp->argv[0], "==") == 0)
+		operator = EQUAL;
+	else if (strcmp(mexp->argv[0], "!=") == 0)
+		operator = NOT_EQUAL;
+	else if (strcmp(mexp->argv[0], ">") == 0)
+		operator = GREATER_THAN;
+	else if (strcmp(mexp->argv[0], "<") == 0)
+		operator = LESS_THAN;
+	else if (strcmp(mexp->argv[0], ">=") == 0)
+		operator = GREATER_THAN_EQUAL;
+	else if (strcmp(mexp->argv[0], "<=") == 0)
+		operator = LESS_THAN_EQUAL;
 	else {
 		format_log(es, "expression has no valid operator: '%s'",
 		    mexp->argv[0]);
@@ -2059,6 +2081,24 @@ format_replace_expression(struct format_modifier *mexp,
 	case MODULUS:
 		result = fmod(mleft, mright);
 		break;
+	case EQUAL:
+		result = fabs(mleft - mright) < 1e-9;
+		break;
+	case NOT_EQUAL:
+		result = fabs(mleft - mright) > 1e-9;
+		break;
+	case GREATER_THAN:
+		result = (mleft > mright);
+		break;
+	case GREATER_THAN_EQUAL:
+		result = (mleft >= mright);
+		break;
+	case LESS_THAN:
+		result = (mleft < mright);
+		break;
+	case LESS_THAN_EQUAL:
+		result = (mleft > mright);
+		break;
 	}
 	if (use_fp)
 		xasprintf(&value, "%.*f", prec, result);
diff --git a/tmux.1 b/tmux.1
index b53c7f04..53687194 100644
--- a/tmux.1
+++ b/tmux.1
@@ -4544,7 +4544,7 @@ multiplication
 .Ql * ,
 division
 .Ql / ,
-and modulus
+modulus
 .Ql m
 or
 .Ql %
@@ -4553,7 +4553,15 @@ or
 must be escaped as
 .Ql %%
 in formats which are also expanded by
-.Xr strftime 3 ) .
+.Xr strftime 3 )
+and numeric comparison operators
+.Ql == ,
+.Ql != ,
+.Ql < ,
+.Ql <= ,
+.Ql >
+and
+.Ql >= .
 For example,
 .Ql #{e|*|f|4:5.5,3}
 multiplies 5.5 by 3 for a result with four decimal places and