You can learn about all of the assumptions that go into Betterment's retirement planning methodology here.
Many of the assumptions that we make can be modified by selecting "Edit Assumptions" in the retirement portion of the Advice Tab in your Betterment account. For more accurate retirement planning advice, you can securely sync external accounts you're using for retirement.
Assumptions you can change include:
- Social Security assumptions
- Age you plan to retire
- Assumed lifespan
- Inflation rate
- Rate of return for synced external accounts
- Annual savings assumptions