To get an estimate of your 2018 tax refund or taxes owed use the TurboTax calculator TaxCaster - https://turbotax.intuit.com/tax-tools/calculators/taxcaster/
To adjust your allowances on a W-4 use the TurboTax W-4 withholding calculator - https://turbotax.intuit.com/tax-tools/calculators/w4/
