diff --git a/src/include/pv.h b/src/include/pv.h
index 74971d2..37ad063 100644
--- a/src/include/pv.h
+++ b/src/include/pv.h
@@ -78,6 +78,13 @@ extern unsigned int pv_getnum_count(const char *, bool);
  */
 extern bool pv_getnum_check(const char *, pv_numtype);
 
+/*
+ * Return an integer representing the first amount as a percentage of the
+ * second total, i.e. 100*amount/total.  If the second value, the total, is
+ * zero or less, return 0.
+ */
+extern int pv_percentage(off_t, const off_t);
+
 /*
  * String handling wrappers.
  */
diff --git a/src/pv/display.c b/src/pv/display.c
index 320b542..3b41c34 100644
--- a/src/pv/display.c
+++ b/src/pv/display.c
@@ -151,21 +151,6 @@ void pv_screensize(unsigned int *width, unsigned int *height)
 }
 
 
-/*
- * Calculate the percentage transferred so far and return it.
- */
-static int pv__calc_percentage(off_t so_far, const off_t total)
-{
-	if (total < 1)
-		return 0;
-
-	so_far *= 100;
-	so_far /= total;
-
-	return (int) so_far;
-}
-
-
 /*
  * Given how many bytes have been transferred, the total byte count to
  * transfer, and the current average transfer rate, return the estimated
@@ -751,7 +736,7 @@ void pv_calculate_transfer_rate(pvstate_t state, bool final)
 		if (state->calc.percentage > 199)
 			state->calc.percentage = 0;
 	} else {
-		state->calc.percentage = pv__calc_percentage(state->transfer.total_written, state->control.size);
+		state->calc.percentage = pv_percentage(state->transfer.total_written, state->control.size);
 	}
 
 	/* Ensure the percentage is never negative or huge. */
@@ -1128,7 +1113,7 @@ bool pv_format(pvstate_t state, bool final)
 		case PV_COMPONENT_BUFPERCENT:
 			/* Transfer buffer percentage utilisation. */
 			if (state->transfer.buffer_size > 0) {
-				int pct_used = pv__calc_percentage((off_t)
+				int pct_used = pv_percentage((off_t)
 								   (state->transfer.read_position -
 								    state->transfer.write_position),
 								   (off_t)
diff --git a/src/pv/number.c b/src/pv/number.c
index edbf97d..2202be6 100644
--- a/src/pv/number.c
+++ b/src/pv/number.c
@@ -280,4 +280,20 @@ bool pv_getnum_check(const char *str, pv_numtype type)
 	return true;
 }
 
+
+/*
+ * Return an integer representing "amount" as a percentage of "total", i.e.
+ * 100*amount/total.  If "total" is zero or less, return 0.
+ */
+int pv_percentage(off_t amount, const off_t total)
+{
+	if (total < 1)
+		return 0;
+
+	amount *= 100;
+	amount /= total;
+
+	return (int) amount;
+}
+
 /* EOF */