Hi Ghosh
You don't need that much - although you could easily spend it!
Generally, an expat will pay $200 to $2000 for accom. If single, you can get somewhere for $200 to 500 (small flat / shared house) etc.
Food shopping cheap.
Going out. Local beer is about $1 or 2. Buy cocktails or go new/expensive places and pay more...
Transport cheap. Minibus taxis less than $1 US but get stuck in traffic. We have Uber. Boda boda motorbikes $1-3 per short commute. Car import tax very high but fuel cheap.
Get health insurance. I pay 600k UGX - about $150 - for one year.
Check out my blog Diary of a Muzungu for more tips about expat life in UG. You'll love KLA! Great city!