on my 1040-SR it shows my standard deduction is 16,550. i am over 65 should it not reflect 18,500?

16,550 is right for 2024.  The 18,500 is for next  year when you do your 2025 tax return.  

For 2024 the standard deduction amounts are:

Single 14,600 + 1,950 for 65 and over or blind (16,550)

HOH 21,900 + 1,950 for 65 and over or blind (23,850)

Joint 29,200 + 1,550 for each 65 and over or blind (30,750/32,300)

Married filing Separate 14,600 + 1,550 for 65 and over or blind (16,150)

Your standard deduction lowers your taxable income. The standard deduction makes some of your income “tax free.”  It is not a refund.  You will see your standard or itemized deduction amount on line 12 of your 2024 Form 1040.

2024 STANDARD DEDUCTION AMOUNTS

SINGLE $14,600    (65 or older/legally blind + $1950)

MARRIED FILING SEPARATELY $14,600    (65 or older/legally blind + $1550)

MARRIED FILING JOINTLY $29,200    (65 or older/legally blind + $1550)

HEAD OF HOUSEHOLD $21,900    (65 or older/legally blind + $1950)

Oh I see what you did.  You added the >65 $1,950 to the 16,550.  The $16,550 already has the >65 added in.    The base Single amount for 2024 is 14,600.