Fidamen

Dollar Cost Averaging Calculator

This calculator projects the future value of a recurring-investment plan (dollar-cost averaging) and provides a lump-sum comparison under the same assumptions. It factors in periodic fees and converts nominal projections into inflation-adjusted (real) terms for purchasing-power perspective.

Use the tool to explore sensitivities: change contribution frequency, assumed long-term return, fees, and inflation. Results are illustrative projections — not guarantees — and should be combined with professional advice for financial decisions.

Updated Nov 9, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record cf4dfb409e1d • Reviewed by Fidamen Standards Committee

Projects future value assuming recurring fixed contributions at regular intervals and compound returns. Fees are applied as a simple periodic deduction; inflation-adjusted results are provided for purchasing-power context.

Inputs

Results

Updates as you type

Projected nominal future value

$16,643.87

Inflation-adjusted future value

$13,653.77

Total contributed

$12,000.00

Approx. annualized return

332.54%

OutputValueUnit
Projected nominal future value$16,643.87USD
Inflation-adjusted future value$13,653.77USD
Total contributed$12,000.00USD
Approx. annualized return332.54%%
Primary result$16,643.87

Visualization

Methodology

Projections use discrete periodic compounding. Annual nominal return is converted to a per-period rate so contributions made at regular intervals can be accumulated.

Fees are approximated as an even annual percentage (expense ratio) applied as a proportional reduction per period. Inflation adjustment divides the nominal future value by the cumulative inflation factor over the full horizon.

This tool provides illustrative, deterministic outputs from user inputs. It does not perform stochastic simulations or tax calculations. Users should validate assumptions and consider backtesting against historical series where available.

Worked examples

Example: $100 monthly for 20 years, 7% annual return, 0.5% fees, 2% inflation — compare projected nominal and real values to a lump-sum of the same total invested at the start.

Use a shorter horizon and lower return to see the effect of fees and inflation on purchasing power; increase contribution frequency to observe compounding cadence effects.

F.A.Q.

Does this calculator guarantee investment performance?

No. Outputs are deterministic projections based on user assumptions. Real market returns vary and can be negative. This tool does not predict future returns.

How are fees and inflation handled?

Fees are approximated as an annual percentage converted to a per-period deduction. Inflation adjustments divide nominal future value by the cumulative inflation factor over the full horizon to estimate real purchasing power.

Should I always prefer DCA over lump-sum investing?

Not necessarily. Historically, lump-sum investing often outperforms DCA when markets generally trend upward, but DCA can reduce short-term timing risk and help with behavioral consistency. Use this comparison alongside risk tolerance and time horizon.

What are the limitations of these formulas?

The model assumes constant periodic returns and fees, contributions of fixed size and timing, no taxes, and no transaction frictions. It does not model volatility drag, sequence-of-returns risk in full stochastic detail, or tax-optimized withdrawal strategies.

How can I improve accuracy?

Use historical total-return series for backtesting, run Monte Carlo scenarios for probabilistic outcomes, incorporate tax rules where relevant, and verify fee assumptions from fund documents.

Sources & citations

Further resources

External guidance

Versioning & Change Control

Audit record (versions, QA runs, reviewer sign-off, and evidence).

Record ID: cf4dfb409e1d

What changed (latest)

v1.0.0 • 2025-11-09 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Public QA status

PASS — golden 25 + edge 120

Last run: 2026-01-23 • Run: golden-edge-2026-01-23

Engine

v1.0.0

Data

Baseline (no external datasets)

Content

v1.0.0

UI

v1.0.0

Governance

Last updated: Nov 9, 2025

Reviewed by: Fidamen Standards Committee (Review board)

Credentials: Internal QA

Risk level: low

Reviewer profile (entity)

Fidamen Standards Committee

Review board

Internal QA

Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person

Semantic versioning

  • MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
  • MINOR: New features or fields that do not change existing outputs for the same inputs.
  • PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.

Review protocol

  • Verify formulas and unit definitions against primary standards or datasets.
  • Run golden-case regression suite and edge-case suite.
  • Record reviewer sign-off with credentials and scope.
  • Document assumptions, limitations, and jurisdiction applicability.

Assumptions & limitations

  • Uses exact unit definitions from the Fidamen conversion library.
  • Internal calculations use double precision; display rounding follows the unit's configured decimal places.
  • Not a substitute for calibrated instruments in regulated contexts.
  • Jurisdiction-specific rules may require official guidance.

Change log

v1.0.0 • 2025-11-09 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: fe1b4f73154a