If you are trying to complete a new W-4 for your husband's job, try the IRS calculator instead. You might also try the paper W-4 so you can review the instructions more carefully.
https://www.irs.gov/individuals/tax-withholding-estimator
https://www.irs.gov/pub/irs-pdf/fw4.pdf
If your spouse is still working, you can expect that 85% of your social security benefit will be taxable, so you can count that as taxable retirement income.
