根据国家税务总局(关于填开增值税专用发票有关问题的通知》(国税发[1996]166号)规定:纳税人以含税单价销售货物或应税劳务的,应换算成不含税单价填开专用发票,如果换算使单价、销售额和税额等项目发生尾数误差的,应按以下方法计算填开:(一)销售额计算公式如下:销售额=含税总收入÷(1+税率或征收率)(二)税额计算公式如下:税额=含税总收入-销售额 According to the Notice of the State Administration of Taxation (Guoshui Fa [1996] No. 166) on the Issue of Filling Out VAT Special Invoices, taxpayers selling goods or taxable services at the tax unit price should be converted into tax-free unit price Open a special invoice, if the conversion unit price, sales and tax items such as the mantissa error, should be calculated as follows: (a) sales calculation formula is as follows: sales = total tax revenue ÷ (1 + tax rate or Levy rate) (B) The tax calculation formula is as follows: Tax = total tax revenue - sales