June 13, 2019

William Dockman
Chief Financial Officer
W R GRACE & CO
7500 Grace Drive
Columbia, MD 21044

       Re: W R GRACE & CO
           Form 10-K for the fiscal year ended December 31, 2018
           Filed on February 28, 2019
           File No. 1-13953

Dear Mr. Dockman:

      We have reviewed your filing and have the following comment. In our
comment, we
may ask you to provide us with information so we may better understand your
disclosure.

       Please respond to this comment within ten business days by providing the
requested
information or advise us as soon as possible when you will respond. If you do
not believe our
comment applies to your facts and circumstances, please tell us why in your
response.

       After reviewing your response to this comment, we may have additional
comments.

Form 10-K for the year ended December 31, 2018

Management's Discussion and Analysis of Financial Condition and Results of
Operations
Analysis of Operations, page F-66

1.    We note you present a ratio you identify as Adjusted EBIT Return on
Invested Capital that
      you calculate using the non-GAAP financial measure, Adjusted EBIT. We
also note you
      do not present this ratio using the most directly comparable GAAP
measure. Please
      ensure all non-GAAP financial measures you present in future filings,
including annual
      and quarterly filings and earnings releases filed under Form 8-K, fully
comply with Item
      10(e) of Regulation S-K.
 William Dockman
FirstName LastNameWilliam Dockman
W R GRACE & CO
Comapany NameW R GRACE & CO
June 13, 2019
Page 2
June 13, 2019 Page 2
FirstName LastName
        We remind you that the company and its management are responsible for
the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action
or absence of
action by the staff.

      You may contact Mindy Hooker at (202) 551-3732 or Anne McConnell at (202)
551-
3709 with any questions.



                                                          Sincerely,

                                                          Division of
Corporation Finance
                                                          Office of
Manufacturing and
                                                          Construction