Using a tax returns online estimator, we can get this broad in about 10-15 minutes. The tax refund estimator tool will need gathering information about you, to make an estimate. All you have to do is make simple entries. These tax items put on to relatively few people. AMT and other misc. Withholding, Federal 2011 tax returns withheld, State income tax withheld and future withholding if before end of tax year.