           x
         </div>
         <div style={flex: 1}>
-          <Input type="number" value={@state.gameWidth * 480 / 800} readOnly />
+          <Input type="number" value={Math.round(@state.gameWidth * 480 / 800)} readOnly />
         </div>
         <div style={flex: 'none', width: 15, paddingLeft: 5}>
           px

         value={@state.gameWidth}
         onChange={@handleSetWebviewWidth.bind @, "webviewWidthRatio"}
         disabled={!@state.useFixedResolution} >
          <option key={-1} value={@state.gameWidth} hidden>{Math.round(@state.gameWidth/8)}%</option>
          {
            i = 0
            while i < 4

        <div style={flex: 1}>
          <Input type="number"
           ref="webviewWidth"
           value={Math.round(@state.gameWidth)}
           onChange={@handleSetWebviewWidth.bind @, "webviewWidth"}
           readOnly={!@state.useFixedResolution} />
        </div>
