The Standard Deduction is a set amount for your filing status. You don't get it for the number of people or for dependents. Only for for primary taxpayer and spouse.
For 2020 the standard deduction amounts are:
Single 12,400 + 1,650 for 65 and over or blind (14,050)
HOH 18,650 + 1,650 for 65 and over or blind
Joint 24,800 + 1,300 for each spouse 65 and over or blind
Married filing Separate 12,400 + 1,300 for 65 and over or blind
