The 2010 Yearbook of American and Canadian Churches reports total church membership of 147,384,631, up 0.49 percent over 2009. The top five churches listed in order of size of membership:

1. The Catholic Church, 68,115,001, up 1.49 percent.
2. Southern Baptist Convention, 16,228,438, down 0.24 percent.
3. The United Methodist Church, 7,853,987, down 0.98 percent.
4. The Church of Jesus Christ of Latter-day Saints, 5,974,041, up 1.71 percent.
5. The Church of God in Christ, 5,499,875, no updates reported.

Churches reporting the highest membership losses:

1. Presbyterian Church (USA), down 3.28 percent to 2,941,412.
2. American Baptist Churches in the USA, down 2 percent to 1,358,351.
3. Evangelical Lutheran Church in America, down 1.92 percent to 4,709,956.

How many years will it take for the LDS Church to overtake the United Methodists and occupy third place? To find out I have assumed the UMC continues with a rate of decline of .98% and the LDS with a steady 1.71% increase. The figures reported in the yearbook are for 2008.

My calculations indicate that by the end of 2019, less than ten years, The Church of Jesus Christ of Latter-day Saints will be the third largest church in the United States.

If the table formatting is scrambled, view the table here.

Year	UMC	-0.98%	LDS	+1.71%
2009	7,853,987	76,969	5,974,041	102,156
2010	7,777,018	76,215	6,076,197	103,903
2011	7,700,803	75,468	6,180,100	105,680
2012	7,625,335	74,728	6,285,780	107,487
2013	7,550,607	73,996	6,393,267	109,325
2014	7,476,611	73,271	6,502,591	111,194
2015	7,403,340	72,553	6,613,786	113,096
2016	7,330,788	71,842	6,726,882	115,030
2017	7,258,946	71,138	6,841,911	116,997
2018	7,187,808	70,441	6,958,908	118,997
2019	7,117,368	69,750	7,077,905	121,032
2020	7,047,617	69,067	7,198,937	123,102

.
Note: The result of the percentage decline or increase is shown in the following year, hence the result of UMC’s forecast -.98% decline of 76,969 in 2009 is shown in 2010 as 7,777,018 (7,853,987 – 76,969).