The winter arithmetic

People × days × calories. Run it in October while there's still time to fix the gap, not in January when there isn't.

Result

Adults2

Children2

Days to cover180

Calories per adult per day2500

Calories you already have stored0

Calories required

1,530,000 cal

2 adults + 2 children × 180 days.

The gap

1,530,000 cal

Gap in wheat, as one example

1,020 lb

About 22.7 five-gallon buckets.

Per person per day you have

0 cal

What this will not do

Calories are not nutrition. This tells you whether you'll have energy, not whether you'll be well. Fat, protein, and vitamin C in particular need planning separately — scurvy is a storage-diet disease, historically.
Run this in October. The gap is fixable in October with a grain order and a few more rows of storage crops. In January it is not fixable at all.
Count what you will actually eat. A year of wheat you don't know how to cook is not food, it's ballast — and appetite fatigue is real and underestimated.

The full build and the reasoning are in Chapter 38 of the guide.