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Coast FIRE & Retirement Pension Calculator

Split your net worth into accessible bridge accounts (ISA / taxable / cash) and age-locked pensions (SIPP 57 / 401k 59.5 / Super 60) to verify whether your liquid bridge survives until pension unlock.

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Jurisdiction & three-bucket portfolio

Unlock age: 57 (SIPP / workplace pension (unlocks 57))

Pension jurisdiction & unlock rule

Display currency

Current age

yrs

Target retirement age

yrs

Accessible bucketISA / GIA / taxable

Locked pension bucketUnlocks at age 57

Current cashHYSA / liquid buffer

Total portfolio: £255,000 (Liquid bridge pool: £160,000 accessible + cash · Locked: £95,000).

P0 bridge spending & real return assumptions

Real return r_real: 2.44%/yr · Bridge shortfall: £28,000/yr

P0 essential annual spendingnon-negotiable floor

Part-time / coast incomeoffsets P0 before unlock

Expected nominal return

Expected inflation rate

Safe withdrawal rate (SWR)4% = 25× P0 spending

Monthly savings (if working)used for earliest Coast solver

How Coast FIRE & Bridge vs. Locked drawdown work

1. Real Return (r_real): Using the exact Fisher equation, r_real = (1 + r_nominal) / (1 + inflation) − 1 = 2.44% per year. Your Full FIRE target at age 60 is P0_Spending / SWR = £700,000, and today's Coast FIRE number is FIRE_Target / (1 + r_real)^22.

2. Bridge vs. Locked Iterative Test: Because locked pensions (UK unlock age 57) cannot be tapped early without severe penalties, your Accessible + Cash pool (£160,000) must absorb the annual gap P0_Spending − Part_Time_Income (£28,000/yr) every year from age 38 to 57 via closing = opening × (1 + r_real) − annual_shortfall.

Result · Coast FIRE & Bridge Verdict

Age 38 → Pension unlock at 57 → Target retirement at 60

Coast FIRE target

£411,963

Compounds at 2.44% real to £700,000 by age 60

Gap to Coast FIRE

£156,963

Current total buckets: £255,000 (62% funded)

Bridge covers to unlock (57)?

No (−£413,709 gap)

First Bridge gap at age 44 (−£21,540 in breach year)

Earliest safe Coast age

Age 54

In 16 years (both Coast target & bridge to 57 met)

Bridge gap detected at age 44 (13 yrs before pension unlock)

Drawing £28,000/yr from your £160,000 accessible + cash pool exhausts liquid funds at age 44 (first-year shortfall −£21,540; cumulative bridge deficit −£413,709 by age 57), even while your locked pension grows untouched to £150,164.

Accessible bridge vs. Locked pension trajectory

Real balances from age 38 to 60 · Vertical dashed line marks pension unlock (57)

Accessible balance (ISA / taxable + cash)Locked pension balance (UK 57)Bridge gap region (< £0 before unlock)

Year-by-year bridge drawdown schedule

Iterative schedule from age 38 to pension unlock at 57

ProBridge vs locked: year-by-year drawdown to pension unlock$19 once

Showing 6 of 19 pre-unlock bridge years (`opening × (1 + r_real) − shortfall = closing`)

Age	Accessible opening	Growth (r_real)	Annual shortfall	Accessible closing	Locked closing
Age 38	£160,000	+£3,902	−£28,000	£135,902	£97,317
Age 39	£135,902	+£3,315	−£28,000	£111,217	£99,691
Age 40	£111,217	+£2,713	−£28,000	£85,930	£102,122
Age 41	£85,930	+£2,096	−£28,000	£60,026	£104,613
Age 42	£60,026	+£1,464	−£28,000	£33,490	£107,164
Age 43	£33,490	+£817	−£28,000	£6,306	£109,778
Unlock @ 57	£160,000	2.44%/yr	−£28,000/yr	−£413,709	£150,164

Included in Pro. Unlock once, keep it on this device.

Built from user complaints

What people hate about the other tools

We read the reviews of the incumbents before writing this page. Every complaint below maps to a decision in the tool above.

Simple FIRE calculators lump all net worth together and ignore that 401k, SIPP, or Super funds are locked until age 57–60 while bridge accounts must last.
r/coastFIRE (Reddit) · ignores locked pension age rules
In this toolSeparates accessible bridge accounts (ISA/Roth/Taxable) from age-locked pensions (SIPP/401k/Super) automatically.
Relying on a single fixed 7% real return ignores sequence-of-returns risk, inflation shocks, and the ability to cut discretionary spending in bad years.
r/coastFIRE & InvestingFire · static return & no spending floor
In this toolRuns 1,000 client-side Monte Carlo simulations with custom inflation regimes and a P0 essential spending floor.
Commercial retirement tools charge $129/year just to save your scenario and wipe all entered data as soon as you close the browser tab on the free tier.
r/coastFIRE (ProjectionLab discussions) · no persistence without $129/yr sub
In this toolPersists your full retirement model in browser localStorage and URL hash links for free with zero login.

One-line difference: No-signup Coast FIRE planner with US/UK/AU locked pension buckets, P0 spending guardrails, and Web Worker Monte Carlo.

How this is paid for

Free forever, Pro when you need the paperwork

Free + one-time Pro

Free no signup, no card

Real return (r_real) Coast FIRE target & net worth growth curve
Basic accessible bridge vs. age-locked pension bucket preview
Auto-saved single or couple plan in localStorage & shareable URL

Pro $19 once

1,000-run Web Worker Monte Carlo & stagflation stress testing
Full US (401k/Roth), UK (SIPP/ISA) & AU (Super) bridge optimizer
Asynchronous couple retirement timelines & P0 spending floor guardrails
Multi-scenario comparison table & printable PDF/CSV roadmap export

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