diff --git a/core/resources/l10n/messages.properties b/core/resources/l10n/messages.properties
index be9630a1d..ee5cb6480 100644
--- a/core/resources/l10n/messages.properties
+++ b/core/resources/l10n/messages.properties
@@ -2030,6 +2030,7 @@ FlightDataType.TYPE_STABILITY = Stability margin calibers
 FlightDataType.TYPE_MACH_NUMBER = Mach number
 FlightDataType.TYPE_REYNOLDS_NUMBER = Reynolds number
 FlightDataType.TYPE_THRUST_FORCE = Thrust
+FlightDataType.TYPE_THRUST_WEIGHT_RATIO = Thrust-to-weight ratio
 FlightDataType.TYPE_DRAG_FORCE = Drag force
 FlightDataType.TYPE_DRAG_COEFF = Drag coefficient
 FlightDataType.TYPE_AXIAL_DRAG_COEFF = Axial drag coefficient
diff --git a/core/src/net/sf/openrocket/simulation/FlightDataType.java b/core/src/net/sf/openrocket/simulation/FlightDataType.java
index 950b0c728..f2ddb02e1 100644
--- a/core/src/net/sf/openrocket/simulation/FlightDataType.java
+++ b/core/src/net/sf/openrocket/simulation/FlightDataType.java
@@ -115,12 +115,14 @@ public class FlightDataType implements Comparable<FlightDataType> {
 	//// Thrust and drag
 	//// Thrust
 	public static final FlightDataType TYPE_THRUST_FORCE = newType(trans.get("FlightDataType.TYPE_THRUST_FORCE"), "Ft", UnitGroup.UNITS_FORCE, 70);
+	//// Thrust-to-weight ratio
+	public static final FlightDataType TYPE_THRUST_WEIGHT_RATIO = newType(trans.get("FlightDataType.TYPE_THRUST_WEIGHT_RATIO"), "Twr", UnitGroup.UNITS_COEFFICIENT, 71);
 	//// Drag force
-	public static final FlightDataType TYPE_DRAG_FORCE = newType(trans.get("FlightDataType.TYPE_DRAG_FORCE"), "Fd", UnitGroup.UNITS_FORCE, 71);
+	public static final FlightDataType TYPE_DRAG_FORCE = newType(trans.get("FlightDataType.TYPE_DRAG_FORCE"), "Fd", UnitGroup.UNITS_FORCE, 72);
 	//// Drag coefficient
-	public static final FlightDataType TYPE_DRAG_COEFF = newType(trans.get("FlightDataType.TYPE_DRAG_COEFF"), "Cd", UnitGroup.UNITS_COEFFICIENT, 72);
+	public static final FlightDataType TYPE_DRAG_COEFF = newType(trans.get("FlightDataType.TYPE_DRAG_COEFF"), "Cd", UnitGroup.UNITS_COEFFICIENT, 73);
 	//// Axial drag coefficient
-	public static final FlightDataType TYPE_AXIAL_DRAG_COEFF = newType(trans.get("FlightDataType.TYPE_AXIAL_DRAG_COEFF"), "Cda", UnitGroup.UNITS_COEFFICIENT, 73);
+	public static final FlightDataType TYPE_AXIAL_DRAG_COEFF = newType(trans.get("FlightDataType.TYPE_AXIAL_DRAG_COEFF"), "Cda", UnitGroup.UNITS_COEFFICIENT, 74);
 	
 	
 	////  Component drag coefficients
@@ -218,6 +220,7 @@ public class FlightDataType implements Comparable<FlightDataType> {
 		TYPE_MACH_NUMBER,
 		TYPE_REYNOLDS_NUMBER,
 		TYPE_THRUST_FORCE,
+		TYPE_THRUST_WEIGHT_RATIO,
 		TYPE_DRAG_FORCE,
 		TYPE_DRAG_COEFF,
 		TYPE_AXIAL_DRAG_COEFF,
diff --git a/core/src/net/sf/openrocket/simulation/RK4SimulationStepper.java b/core/src/net/sf/openrocket/simulation/RK4SimulationStepper.java
index 16cd9fd35..5c3934a0a 100644
--- a/core/src/net/sf/openrocket/simulation/RK4SimulationStepper.java
+++ b/core/src/net/sf/openrocket/simulation/RK4SimulationStepper.java
@@ -623,6 +623,8 @@ public class RK4SimulationStepper extends AbstractSimulationStepper {
 		}
 		
 		data.setValue(FlightDataType.TYPE_THRUST_FORCE, store.thrustForce);
+		double weight = store.rocketMass.getMass() * store.gravity;
+		data.setValue(FlightDataType.TYPE_THRUST_WEIGHT_RATIO, store.thrustForce / weight);
 		data.setValue(FlightDataType.TYPE_DRAG_FORCE, store.dragForce);
 		data.setValue(FlightDataType.TYPE_GRAVITY, store.gravity);