diff --git a/src/main.c b/src/main.c
index 34a5db4..816bd00 100644
--- a/src/main.c
+++ b/src/main.c
@@ -117,7 +117,6 @@ void read_can(Tel *t, int soc) {
                         case 0x382:
                                 if (frame.can_dlc >= 2) {
                                         t->rpm.data = frame.data[0] | (frame.data[1] << 8);
-                                        t->speed.data = (int)(t->rpm.data * 0.017f);
                                 }
                                 break;
                         default:
@@ -151,6 +150,17 @@ void read_uart(Tel *t, int fd, SerialParser *uart_str) {
         }
 }
 
+void calc_data(Tel *t) {
+        t->power.data = (int)(t->tens.data * t->amp.data);
+        t->speed.data = (int)(t->rpm.data * 0.017f);
+
+        if (t->speed.data > 0) {
+                t->eff.data = (float)t->power.data / (float)t->speed.data;
+        } else {
+                t->eff.data = 0.0f;
+        }
+}
+
 long now_ms(void) {
     struct timespec ts;
     clock_gettime(CLOCK_MONOTONIC, &ts);
@@ -534,6 +544,7 @@ int main(int argc, char **argv) {
                                 } else {
                                         if (use_can) read_can(&tel, soc);
                                         if (use_uart) read_uart(&tel, uart_fd, &uart_parser);
+                                        calc_data(&tel);
                                 }
                                 break;
                 }