These are my total costs per month based on a family of 5, (my fiancee pays her own gas, about $500 to food costs, plus buys her own lunches/etc):
Alarm Monitoring $21.50
Internet/Cable/Home Phone $209.00
Cancer Plan $8.90
Health plans$100 (only myself, my fiancee and her kids are covered, the 24 year old needs a plan, it high deductable but I have also free contacts/exams, wellness, $500k in life insurance / AD&D, and my dental is fully covered for my needs)
Flexible Spending $125 (going to increase this, tax free money)
Car Loan $446.61
Car Fuel $300.00
Cell Phones $115.00 (6 phones, one is for a poor kid and his family's only phone, I get reimbursed from my company for my phone plan fully)
Credit Payments $375.00 (My ex-wife's cards I got left with in a divorce plus a $9000 IRS bill I was left with)
DropBox $9.99
Electric $350.00 (average, goes from $250 to $550, turning off unused fans now and that is saving $30-50 a month...I can save more with a $800 investment to move my attic unit a bit)
Food $1,200.00 (working on this)
Fitness $74.00 (couple)
Insurance $295.00 (full 100/300/100 coverage on a 96 Honda Accord and 12 Mazda 3 GT)
Newspaper $0.00 (was $20 a month, I cancelled it 3 years ago and they still deliver)
School Loans $116.91 (<4% interest and a write off)
Sirius $16.50
Water $125.00 (average, getting closer to $90 now I have talked to the kids about starting a shower they don't get into right away)
Water Filter $8.00 (Aquasana)
Dog Food $55.00 (2 cans per day, was $190 a month for Merrick food, now on Kirkland Nature's Domain)
Cat Food/Supplies $150.00 (10 cats, was $72 per week on Science Diet, now on Grreat Choice, not a premium brand; but decent for cats)
Total $3,876.41
So my net expenses per month hovers around $4200, with a gross of $62k a year.
I could definitely cut costs down A LOT more and this doesn't take into account any extras like going out or taking a weekend vacation at a hotel.
I am living in a lower cost area of the major Metropolitan area.
The above also doesn't take into consideration 401K savings and the like, I try to do 10%