How it works
Your outgoings are subtracted from your income. What you deliberately invest becomes the savings rate; what is left over after everything, including those investments, is reported separately as unallocated.
That separation is deliberate. Money invested is committed; money merely left over usually gets spent. Reporting them as one figure would flatter the position, so the calculator keeps them apart and shows what the rate would become if the surplus were directed too.
More detail
The instalment share is shown alongside, because debt service is the one outgoing that is hard to reduce quickly and therefore constrains the rate most.
Nothing is projected. This is one month described, which is the input every long-term projection depends on.
Once you know what you can invest each month, the SIP calculator.
For the position this rate is building towards, use the net worth calculator.