Seasonal Water Yield Quickflow validation

Hello, community!

I’ve run the SWY model using the contribution areas relative to stream gauges stations so I would have data to compare monthly Quickflow data. After compiling the measured data in monthly averages, I transformed the data from m³/s to mm/month, using the formula:

Qf(mm/month) = (Qf(m³/s)/basin area (m²))x1000x3600x24x31 (or 30 or 28, depending on the month).

To get monthy MODELED Qf data, I simply summed all the Qf pixels in the basin, so as to get total Qf per month.
Although I got fair correlation between modeled Qf and measured Qf, the order of magnitude of modeled Qf is very different, being in the magnitude of millions of mm, whereas the measured data is in the magnitude of thousands of mm.

Can someone help?