diff --git a/src/lib/commands/coll.c b/src/lib/commands/coll.c
index 941b2d51..1081e22c 100644
--- a/src/lib/commands/coll.c
+++ b/src/lib/commands/coll.c
@@ -57,9 +57,6 @@ coll(void)
     struct lonstr loan;
     struct sctstr sect;
     coord x, y;
-    long rdur;
-    long xdur;
-    double rate;
     double owed;
     double pay;
     s_char buf[1024];
@@ -79,33 +76,12 @@ coll(void)
     }
     /* If we got here, we check to see if it's been defaulted on.  We
        already know it's owed to this player. */
-    (void)time(&now);
-    /*
-     * split duration now - l_lastpay into regular (up to l_duedate)
-     * and extended (beyond l_duedate)
-     */
-    rdur = loan.l_duedate - loan.l_lastpay;
-    xdur = now - loan.l_duedate;
-    if (rdur < 0) {
-	xdur += rdur;
-	rdur = 0;
-    }
-    if (xdur <= 0) {
+    owed = loan_owed(&loan, time(&now));
+    if (now <= loan.l_duedate) {
 	pr("There has been no default on loan %d\n", arg);
 	return RET_FAIL;
     }
 
-    rate = loan.l_irate / (loan.l_ldur * 8.64e6);
-
-/* changed following to avoid overflow 3/27/89 bailey@math-cs.kent.edu
-	owed = ((rdur * rate) + (xdur * rate * 2.0) + 1.0) * loan.l_amtdue;
-   Begin overflow fix */
-    owed = ((rdur * rate) + (xdur * rate * 2.0) + 1.0);
-    if (((1 << 30) / owed) < loan.l_amtdue)
-	owed = (1 << 30);
-    else
-	owed *= loan.l_amtdue;
-/* End overflow fix */
     pr("You are owed $%.2f on that loan.\n", owed);
     if (!(p = getstarg(player->argp[2],
 		       "What sector do you wish to confiscate? ", buf)))
@@ -137,7 +113,7 @@ coll(void)
     }
     if (sect.sct_type == SCT_CAPIT || sect.sct_type == SCT_MOUNT)
 	caploss(&sect, sect.sct_own, "that was %s's capital!\n");
-    sect.sct_item[I_MILIT] = 1;	/* FIXME no where did this guy come from? */
+    sect.sct_item[I_MILIT] = 1;	/* FIXME now where did this guy come from? */
 
 /* Consider modifying takeover to take a "no che" argument and
    putting using it here again. */
diff --git a/src/lib/commands/fina.c b/src/lib/commands/fina.c
index c2280a22..c41af4f7 100644
--- a/src/lib/commands/fina.c
+++ b/src/lib/commands/fina.c
@@ -52,10 +52,6 @@ fina(void)
     struct lonstr loan;
     struct nstr_item ni;
     time_t now;
-    int rdur;
-    int xdur;
-    double rate;
-    double amt;
 
     if (!opt_LOANS) {
 	pr("Loans are not enabled.\n");
@@ -71,40 +67,12 @@ fina(void)
     while (nxtitem(&ni, (s_char *)&loan)) {
 	if (loan.l_status != LS_SIGNED)
 	    continue;
-	/*
-	 * split duration now - l_lastpay into regular (up to l_duedate)
-	 * and extended (beyond l_duedate)
-	 */
-	rdur = loan.l_duedate - loan.l_lastpay;
-	xdur = now - loan.l_duedate;
-	if (rdur < 0) {
-	    xdur += rdur;
-	    rdur = 0;
-	}
-	if (xdur < 0) {
-	    rdur += xdur;
-	    xdur = 0;
-	}
-
-	if (CANT_HAPPEN(loan.l_ldur == 0))
-	    continue;
-	rate = loan.l_irate / (loan.l_ldur * 8640000.0);
-
-/* changed following to avoid overflow 3/27/89 bailey@math-cs.kent.edu
-		amt = (rdur * rate + xdur * rate * 2.0 + 1.0) * loan.l_amtdue;
-   Begin overflow fix */
-	amt = (rdur * rate + xdur * rate * 2.0 + 1.0);
-	if (((1 << 30) / amt) < loan.l_amtdue)
-	    amt = (1 << 30);
-	else
-	    amt *= loan.l_amtdue;
-/* End overflow fix */
-
 	pr(" %-2d  (%3d) %-8.8s  (%3d) %-8.8s  ", ni.cur,
 	   loan.l_loner, cname(loan.l_loner),
 	   loan.l_lonee, cname(loan.l_lonee));
-	pr("%3d%%   %3d    %5ld    %7d",
-	   loan.l_irate, loan.l_ldur, loan.l_amtpaid, (int)amt);
+	pr("%3d%%   %3d    %5ld    %7ld",
+	   loan.l_irate, loan.l_ldur, loan.l_amtpaid,
+	   (long)loan_owed(&loan, now));
 	if (now > loan.l_duedate)
 	    pr(" (in arrears)\n");
 	else
diff --git a/src/lib/commands/repa.c b/src/lib/commands/repa.c
index b2f2e0ae..69beec96 100644
--- a/src/lib/commands/repa.c
+++ b/src/lib/commands/repa.c
@@ -50,11 +50,7 @@ repa(void)
     int loan_num;
     long payment;
     long owe;
-    long normaltime;
-    long doubletime;
-    double rate_per_sec, amt;
     s_char *cp;
-    time_t now;
     s_char buf[1024];
 
     if (!opt_LOANS) {
@@ -73,36 +69,7 @@ repa(void)
 	pr("You don't owe anything on that loan.\n");
 	return RET_FAIL;
     }
-    (void)time(&now);
-    /*
-     * split duration now - l_lastpay into regular (up to l_duedate)
-     * and extended (beyond l_duedate)
-     */
-    normaltime = loan.l_duedate - loan.l_lastpay;
-    doubletime = now - loan.l_duedate;
-    if (normaltime < 0) {
-	doubletime += normaltime;
-	normaltime = 0;
-    }
-    if (doubletime < 0) {
-	normaltime += doubletime;
-	doubletime = 0;
-    }
-
-    rate_per_sec = loan.l_irate /
-	((double)loan.l_ldur * SECS_PER_DAY * 100.0);
-
-    owe = (long)(loan.l_amtdue *
-		 ((double)normaltime * rate_per_sec + 1.0 +
-		  (double)doubletime * rate_per_sec * 2.0) + 0.5);
-    amt = ((double)normaltime * rate_per_sec + 1.0 +
-	   (double)doubletime * rate_per_sec * 2.0);
-    if (((1 << 30) / amt) < loan.l_amtdue)
-	owe = (1 << 30);
-    else
-	owe = (long)(loan.l_amtdue *
-		     ((double)normaltime * rate_per_sec + 1.0 +
-		      (double)doubletime * rate_per_sec * 2.0) + 0.5);
+    owe = (long)loan_owed(&loan, time(NULL));
     if ((cp = getstarg(player->argp[2], "amount? ", buf)) == 0)
 	return RET_SYN;
     if (!check_loan_ok(&loan))
diff --git a/src/lib/commands/shark.c b/src/lib/commands/shark.c
index 9f0adf22..cad7976b 100644
--- a/src/lib/commands/shark.c
+++ b/src/lib/commands/shark.c
@@ -55,9 +55,6 @@ shark(void)
     struct lonstr loan;
     struct natstr *natp;
     struct natstr *oldie;
-    long rdur;
-    long xdur;
-    double rate;
     double owed;
     long payment;
     s_char buf[1024];
@@ -82,29 +79,11 @@ shark(void)
 	return RET_FAIL;
     }
     /* If we got here, we check to see if it's been defaulted on. */
-    (void)time(&now);
-    /*
-     * split duration now - l_lastpay into regular (up to l_duedate)
-     * and extended (beyond l_duedate)
-     */
-    rdur = loan.l_duedate - loan.l_lastpay;
-    xdur = now - loan.l_duedate;
-    if (rdur < 0) {
-	xdur += rdur;
-	rdur = 0;
-    }
-    if (xdur <= 0) {
+    owed = loan_owed(&loan, time(&now));
+    if (now <= loan.l_duedate) {
 	pr("There has been no default on loan %d\n", arg);
 	return RET_FAIL;
     }
-
-    rate = loan.l_irate / (loan.l_ldur * 8.64e6);
-
-    owed = ((rdur * rate) + (xdur * rate * 2.0) + 1.0);
-    if (((1 << 30) / owed) < loan.l_amtdue)
-	owed = (1 << 30);
-    else
-	owed *= loan.l_amtdue;
     pr("That loan is worth $%.2f.\n", owed);
     natp = getnatp(player->cnum);
     payment = owed * (1.0 + loan.l_irate / 100.0);
@@ -120,7 +99,6 @@ shark(void)
 	   cname(player->cnum), arg, payment);
 	pr("You now own loan #%d.  Go break some legs.\n", arg);
     }
-/*	NAT_DELTA(natp->nat_money, loan.l_loner, payment);*/
     oldie = getnatp(loan.l_loner);
     oldie->nat_money += payment;
     player->dolcost += payment;
diff --git a/src/lib/subs/disloan.c b/src/lib/subs/disloan.c
index bf7db5f3..29d58b68 100644
--- a/src/lib/subs/disloan.c
+++ b/src/lib/subs/disloan.c
@@ -51,14 +51,10 @@
 #include "prototypes.h"
 
 int
-disloan(int n, register struct lonstr *loan)
+disloan(int n, struct lonstr *loan)
 {
     time_t now;
-    time_t normaltime;
-    time_t doubletime;
     time_t accept;
-    double rate;
-    double owe;
 
     if (loan->l_status == LS_FREE)
 	return 0;
@@ -84,30 +80,11 @@ disloan(int n, register struct lonstr *loan)
 	return 1;
     }
 
-    /*
-     * split duration now - l_lastpay into regular (up to l_duedate)
-     * and extended (beyond l_duedate)
-     */
-    normaltime = loan->l_duedate - loan->l_lastpay;
-    doubletime = now - loan->l_duedate;
-    if (normaltime < 0) {
-	doubletime += normaltime;
-	normaltime = 0;
-    }
-    if (doubletime < 0) {
-	normaltime += doubletime;
-	doubletime = 0;
-    }
-
-    rate = ((double)loan->l_irate / 100.0) / (loan->l_ldur * SECS_PER_DAY);
-    owe = ((double)loan->l_amtdue *
-	   (((double)normaltime * rate + 1.0) +
-	    ((double)doubletime * rate * 2.0))) + 0.5;
     pr("Amount paid to date $%ld\n", loan->l_amtpaid);
-    pr("Amount due (if paid now) $%.2f", owe);
-    if (doubletime == 0) {
+    pr("Amount due (if paid now) $%.2f", loan_owed(loan, now));
+    if (now <= loan->l_duedate) {
 	pr(" (if paid on due date) $%.2f\n",
-	   loan->l_amtdue * ((loan->l_duedate - loan->l_lastpay) * rate + 1.0));
+	   loan_owed(loan, loan->l_duedate));
 	pr("Due date is %s", ctime(&loan->l_duedate));
     } else
 	pr(" ** In Arrears **\n");
diff --git a/src/lib/subs/trdsub.c b/src/lib/subs/trdsub.c
index e9990a43..d865efef 100644
--- a/src/lib/subs/trdsub.c
+++ b/src/lib/subs/trdsub.c
@@ -282,3 +282,39 @@ get_outstand(int cnum)
     }
     return loantot;
 }
+
+/*
+ * Return amount due for LOAN at time PAYTIME.
+ */
+double
+loan_owed(struct lonstr *loan, time_t paytime)
+{
+    time_t rtime;		/* regular interest time */
+    time_t xtime;		/* double interest time */
+    double rate;
+    int dur;
+
+    /*
+     * Split interval paytime - l_lastpay into regular (up to
+     * l_duedate) and extended (beyond l_duedate) time.
+     */
+    rtime = loan->l_duedate - loan->l_lastpay;
+    xtime = paytime - loan->l_duedate;
+    if (rtime < 0) {
+	xtime += rtime;
+	rtime = 0;
+    }
+    if (xtime < 0) {
+	rtime += xtime;
+	xtime = 0;
+    }
+    if (CANT_HAPPEN(rtime < 0))
+	rtime = 0;
+
+    dur = loan->l_ldur;
+    if (CANT_HAPPEN(dur <= 0))
+	dur = 1;
+    rate = loan->l_irate / 100.0 / (dur * SECS_PER_DAY);
+
+    return loan->l_amtdue * (1.0 + (rtime + xtime * 2) * rate);
+}