Wellmark Blue Cross and Blue Shield has partnered with H&R Block Inc. to offer an online calculator that business owners can use to estimate their potential savings from the health-care reform small business tax credit. The Tax Credit Estimator is available at www.wellmark.com.  “We want to help small businesses continue to offer health insurance, or encourage them to start offering health benefits to their employees,” said Joe Garcia, Wellmark’s vice president of sales. The Patient Protection and Affordable Care Act authorized tax credits of up to 35 percent of an employer’s premium expenses to companies with 25 or fewer employees that provide health care coverage to their employees.