William, AI thatplans, explains and stress-tests your retirement

When can you actually retire? Three numbers, 1,000 simulated futures, one clear answer.

Private until you save · Planning software, not advice

Learn more

Every piece of retirement. One plan.

Taxes, Social Security, Medicare, Roth conversions and what you spend all run through one engine, so changing one shows you what it does to the rest.

The Monte Climb phone app
Why plan on real data
3.9%
The withdrawal rate that survives 90% of futures over a 30-year retirement.

Morningstar’s 2025 research puts the safe starting withdrawal rate at 3.9%, judged by whether money is still there in 90% of simulated outcomes, not by an average return. That is the question a Monte Carlo test answers for your own numbers, and it is why the answer above is a probability, not a promise.

Source: Morningstar, The State of Retirement Income 2025 · Dec 2025

1 in 3
65-year-olds who may live to 90 or beyond.

Social Security’s own planning guidance: about one out of every three 65-year-olds may live until at least age 90. A plan that stops at 85 quietly bets against a third of retirees. The plan you build here runs to 95 by default, and you can push it further.

Source: Social Security Administration, Retirement Information for Medicare Beneficiaries · 2026

$172,500
Health care in retirement for one 65-year-old, before long-term care.

Fidelity’s 2025 estimate for a 65-year-old retiring this year: $172,500 in Medicare premiums, deductibles and prescriptions over retirement, and it leaves out long-term care entirely. That is a line item, not a rounding error, so the engine charges Medicare premiums and income-based surcharges year by year instead of a flat guess.

Source: Fidelity Investments, 2025 Retiree Health Care Cost Estimate · Jul 2025

48%
Workers who have never estimated what they’ll need each month in retirement.

EBRI’s 2025 Retirement Confidence Survey found only 52% of workers have estimated the monthly income they’ll need. The other half are guessing. The three numbers at the top of this page are that first step, and the engine takes it from there.

Source: EBRI/Greenwald Retirement Confidence Survey 2025, Fact Sheet 3

How it works

Three numbers in.A plan you can test.

  1. 01

    Tell it three numbers

    Your age, your savings and what you spend a month. Enough for a first answer across 1,000 futures.

  2. The Stress Lab after a 40% crash the year they retire and inflation running hot: 85% of futures still reach 94, with William narrating each punch
    02

    Break it on purpose

    The Stress Lab runs 1,000 simulated markets, then lets you throw a crash, hot inflation or a long life at your plan.

  3. William answering from the plan: household income this year and the bridge years before Social Security
    03

    Ask William

    An AI guide, not a licensed adviser. His figures are read from your plan’s own engine, and he asks when a fact is missing.

Try it with your numbers

Four questions your plan answers

Every page reads the same engine, so the numbers agree from one answer to the next.

The Verdict page in Monte Climb
How often does my money last?

The Verdict runs your whole plan through simulated markets, says how often the money lasts, and shows what would move it.

The 1040 worksheet in Monte Climb
What will I owe in taxes?

A 1040 worksheet built from your plan: this year’s return, line by line, and what a Roth conversion would add.

The Social Security page in Monte Climb
When should we claim Social Security?

See what claiming at 62, 67 or 70 does to your income and your odds, for you and your spouse.

The healthcare cost page in Monte Climb
What will healthcare cost?

Coverage before Medicare and on it, with the subsidy and surcharge lines your income would cross.

One plan. One price.

Try everything for 7 days for $1. Cancel before the 7 days are up and you won’t be charged again.

Monte Climb
Everything in the app

One price unlocks every page, every tool and William. No tiers, no add-ons.

$1
for 7 days, then $140 a year

Billed once a year after the trial. No surprise charges.

Start with your numbers
  • Your first answer is free, no account
  • Private until you choose to save
  • Cancel anytime with one email

Renews automatically at $140 a year until you cancel. Cancel anytime by emailing info@monteclimb.com. Prices in US dollars, plus any sales tax that applies.

What you get

  • Will your money last?
    • The Verdict: your odds across 1,000 market futures, to age 95
    • Fix It shows which changes move them, and by how much
    • What if: retire sooner, spend more, see the answer change
  • Ask WilliamAI guide
    • Plain-English answers about your plan, day or night
    • Every figure read from your plan’s own engine
    • Asks when a fact is missing, instead of guessing
  • Pressure-test it
    • Stress Lab: a crash, hot inflation, living to 100
    • See which shock breaks the plan, and what still holds
    • A timeline of what happens each year, on a calendar
  • Plan the taxes too
    • A 1040 worksheet built from your plan, line by line
    • Roth conversions priced in federal and state tax
    • Giving, QCDs and an estate view in the same plan
  • Social Security & health
    • Claiming at 62, 67 or 70, for you and your spouse
    • Coverage costs before Medicare and on it
    • The subsidy and surcharge lines your income would cross
  • All of it, in one place
    • Income, spending and debt in one cash-flow view
    • Holdings and rental properties alongside the plan
    • On your computer and your phone, always in sync

Questions, answered

Is this financial advice?

No. Monte Climb is planning software. It shows what your own numbers do across many simulated market futures and explains the results in plain English. It doesn’t tell you what to buy or sell, and it isn’t investment, tax or legal advice. For decisions with real consequences, check with a licensed professional.

Is William a real person?

No. William is an AI guide built on Anthropic’s Claude. The figures he quotes come from your plan’s own engine, and when a fact is missing he asks instead of guessing. He can still be wrong, so double-check anything important.

What happens to my data?

Your plan is saved to your Monte Climb account so it’s on each of your devices. When you ask William something, your message and the plan details he needs are sent to Anthropic, our AI provider, to write the reply. Payments go through Stripe, so we never see your card. We don’t sell your data. The Privacy Policy has the details.

How does the trial work?

You pay $1 today for 7 days with everything in the app. Unless you cancel before the 7 days are up, your subscription renews automatically at $140 a year, charged to the card you entered, and keeps renewing every year until you cancel.

How do I cancel?

Email info@monteclimb.com. The link opens a cancellation email that’s ready to send. Cancel during the 7-day trial and you won’t be charged the $140.

Who is it for?

People in the United States planning for retirement, whether it’s years away or already here. Taxes, Social Security and Medicare follow US federal and state rules.

What do I need to start?

Three numbers: your age, what you’ve saved for retirement and what you spend in a month. You get an answer right here on this page with no account. Save your plan when you want to go deeper.

Three numbers.One clear answer.

Your age, what you’ve saved and what you spend. It runs in your browser, and nothing is saved until you say so.

Age58Saved$900,000Monthly spend$5,000Show my answer

No account needed for your answer.

monteclimbAI

Monte Climb is retirement-planning software. It shows what your own numbers do across many simulated market futures. It is not investment, tax or legal advice, and William is an AI, not a licensed adviser.

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