In Wikipedia's article SpaceX Falcon-Heavy the section titled [Capabilities](https://en.wikipedia.org/wiki/Falcon_Heavy#Capabilities) has a table comparing maximum payload masses to Falcon 9 for different payload destination. The current numbers there are shown below.

There is probably some fundamental, easy to grasp reason why Heavy can bring 4.2 times as much mass to Mars than F9, but only 3.2 times as much to GTO and only 2.7 times as much to LEO, but I don't know what that would be.

```
Payload            Falcon Heavy   Falcon 9    Ratio
LEO (28,5°)          63,800 kg   22,800 kg    2.68
GTO (27°)            26,700 kg    8,300 kg    3.22
GTO (27°) Reusable    8,000 kg    5,500 kg    1.45  -  does not apply here
Mars                 16,800 kg    4,020 kg    4.18
Pluto                 3,500 kg      - - 

```

**below:** rough plot of ratio versus "altitude" of the three (presumably non-reusable) data points, just to show there is a trend. 

[![enter image description here](https://i.stack.imgur.com/bHp8W.png)](https://i.stack.imgur.com/bHp8W.png)

---

**below:** Artist conception of a Falcon Heavy, from [here](https://en.wikipedia.org/wiki/File:Pad_39_A_Falcon_Heavy_Artist_Cropped.jpg).

[![enter image description here](https://i.stack.imgur.com/SOsGa.jpg)](https://i.stack.imgur.com/SOsGa.jpg)