Annuity Accumulation Calculator: Growth During the Accumulation Phase
Work out what a deferred annuity grows to during its accumulation phase — from an initial premium plus any ongoing contributions, compounding at the credited rate — before it converts to income.
Adjust the inputs and select Calculate for a full breakdown.
Year-by-year growth schedule
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Future value | Total contributions | Total interest earned |
|---|---|---|---|
| $20k + $400/mo · 5% · 10yr | $95,053.10 | $68,000.00 | $27,053.10 |
| $50k + $0/mo · 4% · 15yr (lump only) | $91,015.08 | $50,000.00 | $41,015.08 |
| $10k + $500/mo · 5% · 20yr | $232,643.24 | $130,000.00 | $102,643.24 |
| $100k + $0/mo · 4.5% · 10yr | $156,699.28 | $100,000.00 | $56,699.28 |
How This Calculator Works
Enter the initial premium, any monthly contribution, the credited annual rate, and the accumulation years. The calculator compounds the balance monthly and shows the accumulated value and how much is growth. This models the accumulation (saving) phase, not the later payout phase.
The Formula
Future Value with Regular Contributions
P = starting amount, PMT = monthly contribution, r = monthly rate (annual ÷ 12), n = number of months
Worked Example
A $20,000 premium plus $400 a month for 10 years at 5% accumulates to about $95,053 — with roughly $27,053 of growth. A deferred annuity has two phases: accumulation (your money grows tax-deferred, as modeled here) and annuitization (the balance converts to a stream of income payments). The appeal is tax-deferred growth and, eventually, the option of guaranteed lifetime income — but annuities are complex products with fees and surrender charges this simple projection doesn't capture.
Key Insight
This calculator shows the accumulation phase of a deferred annuity, but annuities are among the most complex and fee-laden financial products, so the clean compound curve hides a lot. Key cautions: annuities often carry significant fees (mortality and expense charges, administrative fees, and rider costs) that reduce the real credited return, and surrender charges can lock your money in for years with steep penalties for early withdrawal — so the liquidity is poor. The rate matters by type: a fixed annuity credits a set rate (closest to this model), while variable annuities depend on underlying investments (not guaranteed) and indexed annuities credit a capped/participation-limited share of an index — so a flat assumed rate oversimplifies both. The genuine benefits are tax-deferred growth (no annual tax on gains during accumulation) and the eventual option to convert to guaranteed lifetime income you can't outlive, which is valuable for some retirees. But for many savers, low-cost tax-advantaged accounts (401(k), IRA) offer tax-deferred growth without the fees and complexity, so annuities are best considered after maxing those, and only after understanding the specific contract's fees, surrender schedule, and guarantees. Treat this figure as a simplified accumulation estimate and read the actual contract closely before committing.
Frequently Asked Questions
How is the annuity accumulation calculated?
The initial premium and each monthly contribution compound at the credited rate (annual rate ÷ 12 per month). $20,000 plus $400/month for 10 years at 5% accumulates to about $95,053, with roughly $27,053 of that being growth — before any fees.
What are the two phases of a deferred annuity?
Accumulation, where your money grows tax-deferred (modeled here), and annuitization (payout), where the accumulated balance converts to a stream of income payments. The appeal is tax-deferred growth and the eventual option of guaranteed lifetime income.
Does this account for annuity fees?
No — and that's a big caveat. Annuities often carry mortality and expense charges, administrative fees, and rider costs that reduce the real credited return, plus surrender charges for early withdrawal. The actual accumulated value can be meaningfully lower than this fee-free projection.
How does the rate depend on annuity type?
A fixed annuity credits a set rate (closest to this model). A variable annuity's return depends on underlying investments and isn't guaranteed. An indexed annuity credits a capped or participation-limited share of an index. A single flat rate oversimplifies variable and indexed products.
Are annuities a good way to save?
They offer tax-deferred growth and optional lifetime income, valuable for some retirees, but they're complex and fee-laden with poor liquidity (surrender charges). Many savers are better served first maxing low-cost tax-advantaged accounts (401(k), IRA). Consider an annuity only after understanding its specific fees, surrender schedule, and guarantees.
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Data Sources & Benchmarks
This calculator draws on 1 independent, dated source. The starting values for credited annual rate are taken from the benchmarks below and refresh whenever the snapshots are updated.
Methodology & Review
The future value compounds a starting premium and a fixed monthly contribution at the credited annual rate, compounded monthly. It models the accumulation phase only; it ignores annuity fees, surrender charges, riders, and the later payout (annuitization) phase, and assumes a constant credited rate.
Written by Ugo Candido · Last updated May 22, 2026.