A great place to *kitten* your goals is http://keto-calculator.ankerl.com/

You enter your personal information (gender, height, current weight, age, typical activity level) and it calculates your base metabolic rate and daily energy expenditure.

You estimate your body fat % (there are links for a few different ways to get a good estimate).

Then you can select absolute grams of net carbs that is your daily goal.
It is usually recommended to stay under 20 g of carbs for your induction period and make sure you maintain ketosis at that level. Once adapted, some people can stay in ketosis at significantly higher carb intake, you can experiment by slowly upping your intake and see if you stay in ketosis. Some people can stay in ketosis at up to 50 g of carbs per day!

You are then given a range of absolute grams of protein that would be heathy, with recommendations depending on how much you plan to exercise and the caloric deficit you choose. Eating too much protein can lead to a production of glucose, which will interfere with your weight loss. Eating too little protein can lead to muscle loss, and lean muscle burns more calories than fat (and means less strength, tone, and definition), so it is counterproductive for dieting.

Finally, you will choose your caloric deficit, which will fix the absolute number of grams of fat which will be your goal.
Deficits about 25% are considered pretty extreme, too much of a deficit will drive your body into 'starvation mode' and derail your weight loss.

Deficits around 20% are considered 'moderate difficulty'. If you are hungry and miserable all the time at a 20% deficit, try a lower value. Diets are only as effective as our commitment to them, don't make things harder than they need to be!

A 15% deficit is considered average and a good starting place. (Unless you are already very athletic and lean, then it's recommended to use an even smaller deficit!)

In the end, you will be presented with your daily goals, both as a percentage of your daily caloric intake, and as absolute values in grams. Both approaches are equivalent if you get pretty close to your intended daily total caloric intake. To keep on track during the day, I created a spreadsheet for myself (I'm a little obsessive, and I like math). I've arranged it so I can copy my 'Totals' from my MFP Food Diary (Calories, Carbs, Fiber, Protein, Fat -- calories are in kcal, the rest in grams), paste them into my spreadsheet and I can see easily my total net carbs in grams, and my percentage of calories in each category.

Note: net carbs can come out wrong if any components of a recipe or meal have more fiber than carbs, but that's not common, and I don't think we need to be so exact on a daily basis anyway.

As for my current goal values and percentages...

I have set my goals rather aggressively, and am seeing fast weight loss when I don't intentionally take a day off for a special occasion and get myself kicked out of ketosis.

I am 5'4, currently ~165 lb, female, 32 yrs old. This gives me a Base Metabolic Rate of 1447 kcal.

I am mostly sedentary (apart from trips to the gym). Therefore my estimated Total Daily Energy Expenditure is 1736 kcal.

I estimate my body fat percentage at 30-35%. So I have approximately 49kg (107lbs) of lean body mass, and 26kg (58lbs) of body fat. This includes about 6kg (13lbs) of essential body fat.

I choose to aim for 20 g of net carbs per day. (I will probably increase these eventually - for now I want to play it safe.)

My recommended protein allotment is between 65g and 92g. Staying on the low end if sedentary, and on the high end if putting my muscles under a lot of stress or eating at a large deficit. I've chosen a goal of about 75 g per day, seems to be working for me so far.

I've chosen a caloric deficit on the high side of moderate at 24% (1320 kcal total). This is probably more aggressive than it needs to be, but I am usually pretty satisfied with a caloric intake between 1200 and 1300 kcal, and I don't stress too much if I exceed my "allotment" on occasion.

Now total calories from selected numbers of grams of net carbs and protein are calculated, and the needed numbers of grams of fat to reach my caloric goal for the day is calculated from the leftover calories. Percentages are calculated from those values.

In summary, my daily goals are currently 1320 kcal total, 20 g (6%) net carbs, 75 g (23%) protein, 104 g (71%) fats!

Our bodies do respond differently, so do experiment with different ratios and deficits until you find the challenge and speed of results you are comfortable with. You will probably also want to re-calculate your goals every 10 lbs or so. As your caloric needs will change with your weight and body fat %!

Good luck on your journey!

Aw, hell if I know. Somewhere around 65/30/5 to 75/24/1, depending on day? I tend to eat the same stuff I have for 2 years now.

I throw a lot of ethanol in there too. Vodka and diet root beer. That doesn't really fit under any macronutrient.

I thought that was what was meant by "percentages don't matter", you can be in ketosis and burning boy fat at 65/30/5 or 80/20/0. What matters is not eating a lot of carbs, not eating too much protein, and filling yourself with fat.

What's most important for the noobs, in my ever so humble opinion, is having ENOUGH calories instead of too little, and realizing that the guideline for grocery shopping should be "8g fat + 8g protein +1g carb" is the easiest allowable starting ratio to follow, just to get them in the habit of buying the right stuff. That comes out to 66.666...% / 29.629...% / 3.703...% That's good, right?