diff --git a/tools/stopwatch.py b/tools/stopwatch.py
index ce2fcea..eb059bc 100644
--- a/tools/stopwatch.py
+++ b/tools/stopwatch.py
@@ -2,16 +2,23 @@ from time import perf_counter_ns
 from .types import IntOrNone
 
 
-def ns_to_string(ns: int) -> str:
+def get_time_string_from_ns(ns: int) -> str:
+    # mis, ns = ns // 1000, ns % 1000
+    # ms, mis = mis // 1000, mis % 1000
+    # s, ms = ms // 1000, ms % 1000
+    # m, s = s // 60, s % 60
+    # h, m = m // 60, m % 60
+    # d, h = h // 24, h % 24
+
     units = ['ns', 'µs', 'ms', 's']
     unit = 0
     while ns > 1_000:
-        ns /= 1_000
-        unit += 1
-        if unit == len(units) - 1:
+        if unit > 3:
             break
+        ns /= 1000
+        unit += 1
 
-    return f"{ns:1.2f}{units[unit]}"
+    return "%1.2f%s" % (ns, units[unit])
 
 
 class StopWatch:
@@ -26,26 +33,26 @@ class StopWatch:
         self.started = perf_counter_ns()
         self.stopped = None
 
-    def stop(self) -> int:
+    def stop(self) -> float:
         self.stopped = perf_counter_ns()
         return self.elapsed()
 
     reset = start
 
-    def elapsed(self) -> int:
+    def elapsed(self) -> float:
         if self.stopped is None:
             return perf_counter_ns() - self.started
         else:
             return self.stopped - self.started
 
-    def avg_elapsed(self, divider: int) -> int:
-        return self.elapsed() // divider  # in ns precision loosing some rounding error probably will not hurt
+    def elapsed_string(self) -> str:
+        return get_time_string_from_ns(self.elapsed())
 
-    def elapsed_string(self):
-        return ns_to_string(self.elapsed())
+    def avg_elapsed(self, divider: int) -> float:
+        return self.elapsed() / divider
 
     def avg_string(self, divider: int) -> str:
-        return ns_to_string(self.avg_elapsed(divider))
+        return get_time_string_from_ns(int(self.avg_elapsed(divider)))
 
     def __str__(self):
         return self.avg_string(1)