Well, you really should. It's not that hard. Most smartphones have an app that will give you a rough idea.

Failing that, follow these rules:

<8k = Sedentary Lifestyle

8-10k = Lightly Active

10-15k = Moderately Active

15k+ = Very Active

These are rough indicators of your lifestyle (excluding all exercise). So if you work in an office all day, then you're likely to be sedentary.

I’ve used evidence-based calculations to create the calculator, so they’re as accurate as you’ll find. However, there is always a degree of personalisation required. Monitor your weight on a daily basis for 2-3 weeks. If your weight moves in the right direction, then you don’t need to make any adjustment. If the scales aren’t moving, then increase or decrease calories accordingly. But make sure you’re 100% sure you’re adhering to the number first. Because, EVERYBODY lies about how much they eat (including me).

No. Your step count estimate needs to EXCLUDE ALL EXERCISE. 

So, don't include any running, gym workouts, and any other planned exercise.

The step count is a reflection of your overall lifestyle.

It’s not necessarily a bad thing to diet below BMR. However, for most people this will probably be a difficult target to stick to on a regular basis. For some people, especially women, chronic dieting on very low calories can lead to health implications. Therefore, broad recommendations are to be less aggressive with your deficit.

This is entirely up to you. A more aggressive calorie deficit is fine, but bear in mind it might be challenging to stick to a very low calorie target. You may find hunger and cravings increase, which may cause frequent bouts of over-eating. Typically, 10-25% will work well for most people, so start here and adjust accordingly.

In terms of a surplus, the sad truth is, you only need a very small increase in calories to build muscle. Start with a 5% surplus and measure progress. 0.5-1kg of total body weight gain per month is a rough target to aim for. If progress is slower, increase calories. If it’s too fast, decrease.

It depends. Although, if you’re making progress, then there’s no need to change anything. If things start to slow down, come back and redo your calculations and see if your target calories have changed. Best bookmark this page, right?

If you lift weights, aim for 1.8-2.7g/kg. If you're only interested in losing weight, you can go as low as 1.2g/kg. 

Also, if you have a lot of body fat to lose, your protein intake might feel quite high. In this case, aim for a slightly lower target.

So you're a carb hater? Ok. Just use the slider to adjust the % of calories apportioned to fat, so that your grams of carbs are <50-100g.

Nope. There's zero evidence to suggest a high protein diet would affect a healthy person in this way. However, if you have an existing kidney issue, it's always a good idea to consult your doctor first.

The calculator will automatically calculate your carbs based on the Protein and Fat numbers you selected. If you want more, or less carbs, simply adjust protein and fat accordingly.

20% of total calories is a good minimum to aim for. But you can go much higher if that’s your preference. As long as you stick to your Target Calories, you’ll still achieve your goal.

If fat is too low, this may have a negative impact of health and hormone production.

For the average person, no. Focus on calories and protein and you'll get great results. Do what you want with carbs and fat to suit your food preferences.