diff --git a/README.md b/README.md
index 018bf52..c507035 100644
--- a/README.md
+++ b/README.md
@@ -52,10 +52,10 @@ The scope of this setting is per TCP session.
 | `report mode`                    | Show current report mode                        |
 | `report mode <off/on>`           | Set report mode                                 |
 | `pwm`                            | Show current PWM settings                       |
-| `pwm <0/1> max_i_pos <width>`    | Set PWM duty cycle for **max_i_pos** to *width* |
-| `pwm <0/1> max_i_neg <width>`    | Set PWM duty cycle for **max_i_neg** to *width* |
-| `pwm <0/1> max_v <width>`        | Set PWM duty cycle for **max_v** to *width*     |
-| `pwm <0/1> <width>`              | Disengage PID, set **i_set** DAC to *width*     |
+| `pwm <0/1> max_i_pos <ratio>`    | Set PWM duty cycle for **max_i_pos** to *ratio* |
+| `pwm <0/1> max_i_neg <ratio>`    | Set PWM duty cycle for **max_i_neg** to *ratio* |
+| `pwm <0/1> max_v <ratio>`        | Set PWM duty cycle for **max_v** to *ratio*     |
+| `pwm <0/1> <volts>`              | Disengage PID, set **i_set** DAC to *volts*     |
 | `pwm <0/1> pid`                  | Set PWM to be controlled by PID                 |
 | `pid`                            | Show PID configuration                          |
 | `pid <0/1> target <value>`       | Set the PID controller target                   |
diff --git a/src/main.rs b/src/main.rs
index 6faa96b..84a2b00 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -273,13 +273,13 @@ fn main() -> ! {
                                     );
                                 }
                                 Command::Pwm { channel, pin, duty } => {
-                                    let duty = duty as u16;
-
-                                    fn set_pwm_channel<P: hal::PwmPin<Duty=u16>>(pin: &mut P, duty: u16) -> u16 {
-                                        pin.set_duty(duty);
-                                        pin.get_max_duty()
+                                    fn set_pwm_channel<P: hal::PwmPin<Duty=u16>>(pin: &mut P, duty: f64) -> (u16, u16) {
+                                        let max = pin.get_max_duty();
+                                        let value = (duty * (max as f64)) as u16;
+                                        pin.set_duty(value);
+                                        (value, max)
                                     }
-                                    let max = match (channel, pin) {
+                                    let (value, max) = match (channel, pin) {
                                         (_, PwmPin::ISet) =>
                                             // Handled above
                                             unreachable!(),
@@ -300,7 +300,7 @@ fn main() -> ! {
                                     };
                                     let _ = writeln!(
                                         socket, "channel {}: PWM {} reconfigured to {}/{}",
-                                        channel, pin.name(), duty, max
+                                        channel, pin.name(), value, max
                                     );
                                 }
                                 Command::Pid { channel, parameter, value } => {