This is getting into a study of economics, but we can probably boil it down to some simple principles that you can turn into a formula.
First off, you need to 'know' your societies minimums. These are pretty easy to figure out, just say to yourself 'What are MY minimums?'
I need food
I need water
I need shelter
I need heat
Give me all that, and I can 'survive'
So that's the stuff that society needs in order to exist.
Now work out how much of the above you need?
FOOD
I need 2000Kcal of food a day. [So I looked at a chart][1]
For beef there's an average 223.6 Cal's per 100 grams of meat. That means I need (rounded) 900 grams of meat a day. Cows weigh 700 ~ 900 Kilograms, but wild animals are probably a fair bit lower in weight than that, so lets just say that 1 animal is going to weigh 500 Kilograms. After Skinning, gutting a deboning you will be left with approximately 1/2 the weight of the animal as food. So your average wild cow is going to give you 250Kg of Meat.
That is 278 meals worth of meat.
That means you can support a society of 278 people with 1 hunter getting 1 kill every single day! (damn good hunter)
WATER
Water, you need about 2 Litres a day if you're not a heavy labourer, and lets just say that your society works pretty hard, so everyone gets 3 litres of water a day.
Water is HEAVY. This is the number one reason why societies exist around tributaries and oceans. Water is going to require a lot of man power to get and distribute.
I can't remember the exact details of how much weight an average person can carry, and how much weight/time a person can work a day. But lets say that you can carry 40kg all day, 80kg for half a day, 160kg for 6 hours.
So I'm going to just stab in the dark, and say that your labourer can carry 160Kg of water a day. He's going to go fill water skins, then lug the water to the people in the village, and he's going to do that all day. (What a life).
160kg of water is 160 Litres, Lets trim that down to 140kg of water, and 40kg of water skins. 140kg of water 'waters' (rounded down) 46 people.
Lets use the food as the basis for your calculations here.
So 278 people, need 834 Litres of water.
834 Litres of water requires (rounded) 6 people to carry water all day, every day.
Your civ of 7 people, can support 278
SHELTER
Shelter is pretty simple, it's something that takes a long time to 'build' And let's face it, no society of 200+ people is going to be living in caves (Yes I know History has plenty of societies that have lived in caves, but these were environments where caves were common features of the land.)
Log Cabins are going to be your easiest bet, (unless you want everyone living in tents.) A log cabin will take 4 people about 20 weeks to build. (Numbers vary, and it's pretty hard to pin this down to an exact number).
So you need 4 people, and 140 days to build a house. You build 2.6 houses a year, a house can have... 4 people?
*Your civ has 7+(4*x) people, can support 278 - You can build homes for 10*x people a year.*
Heating
Primitive Tech = Fire!!!
You need to carry firewood (I'm totally pulling the below numbers out of thick air here, so take it with a pinch of salt).
Lets use the same numbers as were used for water. Your wooders can collect 160Kg of wood a day. Pine is about 530Kg per cubic meter.
You need about 10 pieces of wood to heat a house a day, so going off childhood memories, I'm guessing you need about 1/8th of a cubic meter, so (530/8) You need 67Kg of wood per home. Home has 4 people, 67/4 = 16.5Kg of wood per person. You have 278 people, you need 4587 Kg of wood, you need 29 people to carry wood.
*Your civ has 1+6+(4*x)+29 people, can support 278 - You can build homes for 10*x people a year.*
Now calculating tools is pretty esoteric, I think a tool should last at least 6 months on average, unless it's an axe which I expect should last 3 months? But how long does it take to make an axe? 4 hours? So you can make 2 axes a day. You need 29 axes every 3 months. You make 2 axes a day, 365 days a year, you need 116 axes a year, and you make 182 a year. That's 1 person making axes, and you have a surplus. (woohoo surplus).
*Your civ has 1(hunter)+6(water)+(4(builder)*x)+29(wooder)+1(axer) people, can support 278 - You can build homes for 10*x people a year.*
And I'm just going to throw the same numbers from above down for any other tool you need. Lets say you have 10 types of tools. Axes, Hammers, Bows, Spears, Fletchers, Plows, Baskets, Clothing, Leather works, blahhh... And each person in your society is going to get 8 tools a year... because why not.
*Your civ has 1(hunter)+6(water)+(4(builder)*x)+29(wooder)+1(axer)+9(other tools) people, can support 278 - You can build homes for 10*x people a year.*
So since this is getting really long, lets turn this into a formulae and you can plug in any other careers you want.
** UNIVERSAL FORMULAE ** (hyperbole)
*Your civ has 1(hunter)+6(water)+(4(builder)*x)+29(wooder)+1(axer)+9(other tools) people, can support 278 - You can build homes for 10*x people a year.*
People = X
Hunter = People / 278
Water = people / 46
Wooder = (People*16.5) / 160
Tools = (People * 8) / 182
And Builders are dependent on Population Growth and structure decay, so nerf the numbers to your liking.
With lets say 1685 people You will need. (Rounding every job up)
People = 1685
Hunters = 1685 / 278 = 7 Hunters
Water = 1685 / 46 = 37 Waterers
Wooders = (1685*16.5) / 160 = 174 Wooders
Toolers = (1685 * 8) / 182 = 75 Tool Makers
You have used: 293 People, to support your society, and you have 1392 people with no job.
Do some Algebra, and I think you have something like this:
People = (x/278) + (x/46) + (x*16.5 / 160) + (x*8 / 182)
Solve for X
Hope this helps :)