This calculator estimates how much U.S. paint-maker PPG Industries can afford to pay to buy its Dutch rival Akzo Nobel. The question is how much in synergies could be found by combining the two companies.

PPG's offer of 83 euros a share has been rejected. At that price, it would deliver an implied return on investment of 5.2 percent, before the effect of any cost savings or revenue uplift.

Akzo Nobel's cost of capital is 8.3 percent, according to Morningstar analysts. To reach that hurdle would require 965 million euros of synergies.

We have assumed that a bid of at least 90 euros a share would be necessary to sway Akzo Nobel, which would translate into 1.16 billion euros of synergies required, or about 4.6 percent of the combined costs of the two companies. The proportions for other mergers in the industry have been provided for comparison.

You can use your own offer price and return on investment assumptions.

The return on investment is calculated by dividing Akzo Nobel's net operating profit after tax by the enterprise value of the deal. Estimates from analysts are used in the calculations.

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