Couples FI Planner

Most FIRE calculators assume one person, one retirement date, and one pile of money. Households rarely look like that. This planner projects a two-person balance sheet year by year and reports the first year the combined portfolio covers the household FI target, along with each partner’s age in that year.

It keeps three things separate that single-person calculators collapse together: expenses that belong to the household versus each partner, assets held jointly versus individually, and the year each partner stops contributing. Because savings stop at each partner’s own retirement age, one person retiring early shows up as a real reduction in contributions rather than an unchanged savings rate.

The planner also treats a pension as a target reducer, not an asset. Fixed income that starts at a given age lowers the spending your portfolio must cover from that age on, which drops the target portfolio in a single step — often the most consequential number in a couples plan and the one hardest to see in a single-person tool.

Alongside the FI year you get a retirement checkpoint for each partner: what the portfolio is projected to hold at their chosen retirement age, what the target is at that point, and the shortfall or surplus between them.

It is aimed at households where the two people are not on the same schedule or the same balance sheet.

• Couples with an age gap, where one partner reaches Medicare, Social Security, or a pension start age years before the other.
• Households where one partner wants to stop working early and the other intends to keep going — the classic one-retires-first plan.
• Partners who keep finances partly separate and want personal expenses, personal assets, and personal savings tracked individually rather than pooled.
• Anyone with a defined-benefit pension, teaching or public-sector pension, or annuity that begins at a specific age and permanently lowers the portfolio’s job.
• Couples comparing a 3.5%, 4%, and 5% household withdrawal target to see how many years separate the conservative and aggressive versions of the same plan.

The model runs in real (inflation-adjusted) dollars: expenses stay constant in today’s money and the portfolio grows at a real return, so no inflation input is required. Everything is computed in your browser.

1. 1.Pool the starting portfolio

   Shared assets and both partners’ personal assets are summed into a single household portfolio. The split matters for how you think about the plan, not for the projection arithmetic.

   portfolio_0 = shared_assets + partner_a_assets + partner_b_assets

2. 2.Total the household expenses

   Shared expenses plus each partner’s personal expenses give total annual household spending, held constant in real terms across the projection.

   total_expenses = shared_expenses + partner_a_expenses + partner_b_expenses

3. 3.Subtract fixed income once each pension starts

   In every projection year, each partner’s pension counts only if that partner has reached their pension start age. Fixed income reduces the spending the portfolio must fund, floored at zero.

   net_spend_t = max(0, total_expenses - pension_income_at_age_t)

4. 4.Capitalise net spending into a moving target

   The target portfolio for each year is that year’s net spend divided by the household withdrawal target. Because pensions change net spend, the target is a step function rather than a flat line.

   target_portfolio_t = net_spend_t / withdrawal_target

5. 5.Contribute only while each partner is working

   A partner’s annual savings are added each year until they reach their own retirement age, then stop. A household where one partner retires at 55 and the other at 58 contributes at three different rates over that stretch.

   contributions_t = (age_a < retirement_age_a ? savings_a : 0) + (age_b < retirement_age_b ? savings_b : 0)

6. 6.Roll the portfolio forward and find the crossing

   Each year the portfolio compounds at the real return and receives that year’s contributions. The FI year is the first year the portfolio equals or exceeds the target for that year. The projection runs to age 95 for the younger partner, or at least 40 years.

   portfolio_t+1 = portfolio_t x (1 + real_return) + contributions_t
   FI year = first t where portfolio_t >= target_portfolio_t

7. 7.Report per-partner checkpoints and milestone crossings

   At each partner’s retirement age the planner records the projected portfolio, that year’s target, and the shortfall between them. It then repeats the crossing search at 5%, 4%, and 3.5% withdrawal targets.

Each partner has their own block of inputs; three fields describe the household. All dollar amounts are annual and in today’s dollars.

Current age and retirement age (per partner)

Age today, and the age at which that partner stops contributing savings. Retirement age must be at or above current age, and both are capped at 90. The two ages drive the staggered-contribution behavior that makes this a couples model.

Personal expenses (per partner)

Annual spending attributable to one partner — their car, hobbies, individual insurance, support for their own family. Kept separate from shared costs so you can see who drives the household number.

Personal assets (per partner)

Invested assets in that partner’s name, including their 401(k), IRA, and individual brokerage accounts.

Annual savings (per partner)

That partner’s yearly contributions while still working. Contributions stop the year they reach their retirement age.

Pension amount and pension start age (per partner)

Annual fixed income and the age it begins. It is counted only from that age onward and reduces net spending rather than adding to the portfolio. A pension amount above zero requires a start age.

Shared expenses

Annual household spending neither partner owns individually: housing, utilities, groceries, childcare, shared insurance and travel.

Shared assets

Jointly held invested assets — joint brokerage, shared cash reserves, and other pooled balances.

Real return

Expected annual portfolio return after inflation, accepted between -2% and 10%. Because the model is in real dollars, this is the only growth input.

Withdrawal target

The household withdrawal rate used to convert net spending into a target portfolio, accepted between 2% and 10%. The planner separately reports crossings at 5%, 4%, and 3.5%.

Results are grouped into the household FI year, the current funded position, and per-partner checkpoints.

FI year and ages at FI

The first projection year the portfolio meets that year’s target, with both partners’ ages in that year. Blank if the projection never crosses inside the horizon.

FI before retirement (per partner)

Whether the household reaches FI at or before each partner’s chosen retirement year. A false value on one partner means that person’s planned date arrives before the household is funded.

Current funded percentage

Today’s combined portfolio divided by today’s target portfolio. This is the household equivalent of a single-person FI progress bar.

Current net spend and target portfolio

Total household expenses less any pension income already flowing today, and that figure capitalized at your withdrawal target.

Retirement checkpoints

For each partner: their retirement year and age, the projected portfolio at that point, the target then, and the shortfall. A negative shortfall is a surplus.

Milestone crossings

Target portfolio today and the projected crossing year and ages at 5%, 4%, and 3.5% withdrawal targets — the cost, in years, of a more conservative household plan.

Projection table and chart

Year-by-year ages, working status for each partner, fixed income, net spend, moving target, contributions, portfolio balance, and funded percentage.

These are the values behind the "Try example" button — Maya has a pension starting at 60 and retires at 58; Ethan has no pension and retires at 55.

1. The starting portfolio is $120,000 shared plus $430,000 and $370,000 personal = $920,000.
2. Total household expenses are $28,000 shared plus $48,000 and $36,000 personal = $112,000 a year.
3. No pension is flowing yet, so today’s net spend is the full $112,000 and the target portfolio is $112,000 / 0.04 = $2,800,000. The household is 32.9% funded.
4. Combined contributions run at $57,000 a year while both work, drop to $32,000 when Ethan retires at 55, and stop entirely when Maya retires at 58.
5. Compounding at a 5% real return, the portfolio first meets the $2,800,000 target in 2040, when Maya is 50 and Ethan is 51 — five years before Ethan’s planned retirement date, so both partners clear their checkpoints.
6. At a 5% target the crossing arrives in 2037 (Maya 47); at 3.5% it slips to 2042 (Maya 52). The spread between an aggressive and a conservative household plan is about five years.
7. Maya’s pension only begins in 2050, at age 60. From that year the target drops from $2,800,000 to $88,000 / 0.04 = $2,200,000 — a $600,000 reduction that arrives a decade after FI in this scenario.

The timing of the pension is the lesson here. $24,000 a year of fixed income removes $600,000 from the target, but only from age 60 — long after this couple reaches FI. Move the start age earlier and the target drops during the years that actually decide the plan; leave it at 60 and the household has to be fully funded without it.

This planner is a deterministic real-dollar model. The simplifications below are the ones most likely to matter for a couple.

• Everything is in real dollars at a single real return, with no market volatility and no sequence-of-returns risk. Expenses never change in real terms and never step down when children leave home or a mortgage is paid off.
• Pension income is treated as fixed and permanent from its start age, with no cost-of-living adjustment, no survivor reduction, and no early-claiming haircut.
• Taxes are not modeled. Filing status, the tax difference between joint and individual accounts, and the tax cost of drawing from a pre-tax account are all outside the model — include expected taxes in your expense figures.
• Social Security is not built in. Enter each partner’s expected benefit as a pension with the age you plan to claim if you want it counted.
• Contributions stop exactly at each retirement age; part-time income, a phased exit, or a barista-FIRE stretch cannot be modeled directly. Approximate them by reducing savings and raising the retirement age.
• The withdrawal target is applied to the household as a whole, and healthcare between an early retirement date and Medicare eligibility is not priced separately — a substantial real cost for couples retiring in their 50s.
• The projection runs to age 95 for the younger partner or 40 years, whichever is longer, and results are illustrative estimates rather than personalised financial, tax, or investment advice.

Household FI target

Total household spending net of fixed income, divided by the withdrawal rate. Unlike a single-person FI number it moves over time, because pensions and other fixed income start at specific ages.

Staggered retirement

A plan where partners stop working in different years. It reduces household contributions in steps and often means one partner’s employer healthcare covers the other through part of the gap.

Pension as a target reducer

Fixed income can be treated either as an asset (capitalizing it at the withdrawal rate) or as a reduction in the spending the portfolio must fund. This planner does the latter, which is the more conservative and more legible treatment.

Real versus nominal returns

A real return is the return after inflation. Modelling in real dollars keeps every figure comparable to today’s prices and removes the need for a separate inflation assumption.

Funded percentage

Current portfolio divided by the current target. It is a better progress signal than a raw balance because it moves when either spending or assets change.

• Can I FIRE Yet? CalculatorFor a single balance sheet: separates FIRE-ready assets from home equity and models a cash bridge to portfolio handoff.
• Coast FIRE CalculatorFor the earlier question: the balance that compounds into a full FI number with no further contributions, so one partner can take a pay cut without moving the date.
• Roth Conversion & Capital Gains Headroom PlannerFor couples retiring before Medicare: how much you can convert or realize per year without crossing an ACA subsidy or bracket threshold.
• The FIRE Movement ExplainedThe underlying math a household FI plan rests on, including withdrawal rates and savings-rate mechanics.
• All Stoke planning toolsThe full set of free FIRE calculators and planners.