How do you calculate synergies to break even when a deal is initially dilutive?

Calculate the EPS shortfall between standalone acquirer EPS and pro-forma EPS before synergies. Multiply the shortfall by pro-forma shares to get after-tax net income needed. Gross it up by 1 minus tax rate to get pre-tax synergies required. Formula: pre-tax synergies to break even = EPS dilution x pro-forma shares / (1 - tax rate).