Published model

Membership Flow Model

A transparent cohort-flow estimate that starts with reported 1950 membership, adds reported converts and estimated children-of-record baptisms, and subtracts modelled deaths, members reaching record-retention age limits, and names removed.

This is an accounted-membership scenario model, not a measure of religious activity, belief, attendance, or self-identification.

Open chart Download model JSON
Latest central estimate 15,943,697

2025 membership-flow model output

Scenario band 15,402,673-16,484,721

Low-retention to high-retention estimate

Official comparison 17,887,212

Reported membership for the same year

Central difference -1,943,515

-10.87% from official

Scenario range

Modeled membership flow

Open chart
06.4M13M19M19501969198820062025
Official membership High-retention estimate Central estimate Low-retention estimate

Children of record are not same-year member additions

A new child of record is a child added to church records before baptism. The cleaner membership-addition event is the child-of-record baptism, usually around age 8. The church has not consistently reported that baptism count in recent years, so this model uses the child-of-record baptism estimate already present in the data table.

Children from this pipeline can later appear in convert baptisms if they are baptized at age 9 or older. That means convert baptisms and the child pipeline are not fully independent populations.

Children of record

Intake, baptism, and estimated pipeline gap

Open chart
-10K38K86K134K19501969198820062025zero
New children of record Estimated child-of-record baptisms Estimated not baptized from 8-year-prior intake

Formulas

Central estimate

central[t] = central[t-1] + converts[t] + child_of_record_baptisms[t] - deaths_of_active_members[t] - inactive_members_reaching_age_110[t] - names_removed[t]

High-retention scenario

high[t] = high[t-1] + converts[t] + child_of_record_baptisms[t] - deaths_of_active_members[t] - inactive_members_reaching_age_110[t] - 0.75 * names_removed[t]

Low-retention scenario

low[t] = low[t-1] + converts[t] + child_of_record_baptisms[t] - deaths_of_active_members[t] - inactive_members_reaching_age_110[t] - 1.25 * names_removed[t]

Gone inactive

current_year_converts * 0.9 + prior_year_active_mormons * 0.015

Deaths of active members

round(prior_year_active_mormons * current_year_mormon_death_rate_per_1000 / 1000, 0)

Inactive members reaching age 110

cohort_age_110_births + cohort_age_103_to_110_convert_children + older_convert_cohort_average * recent_unremoved_intake_share, all scaled by prior inactive share

Names removed

round(prior_year_gone_inactive * 0.2, 0)

Active members

prior_year_active_mormons + current_year_new_children_of_record + current_year_converts - current_year_deaths_of_active_members - current_year_gone_inactive

Inactive members

prior_year_inactive_mormons + current_year_gone_inactive - current_year_inactives_reaching_age_110 - current_year_names_removed

Activity rate

current_year_active_mormons * 100 / current_year_official_membership_total

Assumptions

Starting population

The model starts from the reported membership total in 1950.

Confidence: medium

Membership additions

Convert baptisms and children-of-record baptisms are treated as membership additions. New children of record are not treated as same-year member additions.

Confidence: high for recent official reports; lower for estimated historical cells

Children-of-record pipeline

New children of record are record-intake events for children who are not yet baptized. They become membership additions only if later baptized as children of record, usually around age 8. Those baptized at age 9 or older are counted in convert baptisms, so the pipeline can leak into the convert statistic.

Confidence: medium for the concept; low to medium for post-reporting-gap estimates

Lost-file age limit

The church reportedly removes lost-file records when they reach age 110. This model therefore treats inactive members reaching age 110 as record exits. Any active members older than 110 are assumed to be few enough that their effect on aggregate totals is negligible.

Confidence: medium for the rule; low to medium for the exact cohort estimate

Losses

Deaths of active members, inactive members reaching age 110, and names removed are treated as record exits. These fields are model inputs, not official annual report categories.

Confidence: low to medium

Uncertainty band

The high- and low-retention scenarios vary the names-removed component by plus or minus 25%. The band is a sensitivity test, not a statistical confidence interval.

Confidence: medium as a sensitivity display; low as a probability statement

Activity excluded

No attendance, belief, or activity adjustment is applied directly to official membership. Activity proxies are useful comparison indicators but should not be subtracted directly from membership records.

Confidence: high

Latest model inputs

Inputs used for the 2025 model year. These are also available from the data table cell detail views.

InputRoleValueProvenanceFormula
Official membershipcomparison17,887,212official reportn/a
Convert baptismsaddition385,490official reportn/a
Children-of-record baptismsaddition76,704.29estimateChildren of record from 8 years prior * current CoR baptism rate
New children of recordpipeline intake91,835official reportn/a
Births to active memberspipeline intake69,365unknownn/a
Convert children of recordpipeline intake26,945unknownn/a
Gone inactiveloss420,176.07analytical modelcurrent_year_converts * 0.9 + prior_year_active_mormons * 0.015
Deaths of active membersloss43,941analytical modelround(prior_year_active_mormons * current_year_mormon_death_rate_per_1000 / 1000, 0)
Inactive members reaching age 110loss21,224.22analytical modelcohort_age_110_births + cohort_age_103_to_110_convert_children + older_convert_cohort_average * recent_unremoved_intake_share, all scaled by prior inactive share
Names removedloss57,401analytical modelround(prior_year_gone_inactive * 0.2, 0)
Active memberscomparison4,895,545.88analytical modelprior_year_active_mormons + current_year_new_children_of_record + current_year_converts - current_year_deaths_of_active_members - current_year_gone_inactive
Inactive memberscomparison12,949,380.12analytical modelprior_year_inactive_mormons + current_year_gone_inactive - current_year_inactives_reaching_age_110 - current_year_names_removed
Activity ratecomparison27.37analytical modelcurrent_year_active_mormons * 100 / current_year_official_membership_total

Recent model outputs

YearLow-retentionCentralHigh-retentionOfficialCentral minus officialChild baptism input
202515,402,67315,943,69716,484,72117,887,212-1,943,51576,704
202415,077,39515,604,06916,130,74317,509,781-1,905,71278,504
202314,823,24315,335,83315,848,42217,255,394-1,919,56182,339
202214,627,11315,124,43115,621,75017,002,461-1,878,03083,698
202114,435,71514,924,12415,412,53416,805,400-1,881,27683,058
202014,314,36814,788,39915,262,42916,663,663-1,875,26487,963
201914,202,61814,667,24815,131,87916,565,036-1,897,78886,292
201813,969,03414,423,92114,878,80816,313,735-1,889,81486,756
201713,811,29014,243,70114,676,11216,118,169-1,874,46886,200
201613,610,12514,028,52014,446,91615,882,417-1,853,89788,946
201513,396,03813,800,60214,205,16615,634,199-1,833,59767,500
201413,197,77513,585,79013,973,80515,372,337-1,786,54767,741