In general. A payment of estimated tax by an individual shall be determined on Form 1040-ES. For the purpose of determining the estimated tax, the amount of gross income which the taxpayer can reasonably expect to receive or accrue, depending upon the method of accounting upon which taxable income is computed, and the amount of the estimated allowable deductions and credits to be taken into account in computing the amount of estimated tax, shall be determined upon the basis of the facts and circumstances existing at the time prescribed for determining the estimated tax, as well as those reasonably to be anticipated for the taxable year. If, therefore, the taxpayer is employed at the date prescribed for making an estimated tax payment at a given wage or salary, the taxpayer should presume, in the absence of circumstances indicating the contrary, for the purpose of the estimated tax payment that such employment will continue to the end of the taxable year at the wage or salary received by the taxpayer as of such date. In the case of income other than wages and salary, the regularity in the payment of income, such as dividends, interest, rents, royalties, and income arising from estates and trusts is a factor to be taken into consideration. Thus, if the taxpayer owns shares of stock in a corporation, and dividends have been paid regularly for several years upon the stock, the taxpayer should, in the absence of information indicating a change in the dividend policy, include the prospective dividends from the corporation for the taxable year as well as those actually received in such year prior to determining the estimated tax. In the case of a taxpayer engaged in business on his own account, there shall be made an estimate of gross income and deductions and credits in the light of the best available information affecting the trade, business, or profession.

Computation of estimated tax. In computing the estimated tax the taxpayer should take into account the taxes, credits, and other amounts listed in § 1.6654-1(a)(4).