712
Asset allocation by age — stocks vs bonds by rule
Age 35, $100,000, 110 minus age: 75% stocks ($75,000 — US $52,500 / international $22,500) and 25% bonds ($25,000). The calculator below re-splits any age, portfolio, and rule.
★ MONEY · GROWTH · INVESTING
Asset Allocation by Age Calculator: Stocks vs Bonds
At 35 with $100,000, the 110-minus-age rule puts 75% in stocks ($75,000) and 25% in bonds ($25,000). The stocks split into $52,500 US and $22,500 international. Try the other rules — 100 minus age, 120 minus age, and the target-date glide path — and see how the split moves with your age.
How asset allocation by age works
Asset allocation is the split of a portfolio between stocks, which grow fast but swing hard, and bonds, which grow slowly but hold steady. The age rules on this page are shortcuts for that split: the older you are, the less time you have to recover from a crash, so the less of the portfolio sits in stocks. The best-known shortcut is 110 minus age: at 35, stocks are 110 − 35 = 75% and bonds are the remaining 25%. The stocks then split 70% US and 30% international, a simple home-bias split that keeps most of the money at home while still owning the rest of the world.
At the defaults — age 35, a $100,000 portfolio, the 110-minus-age rule — the split is 75% stocks and 25% bonds: $75,000 in stocks and $25,000 in bonds. The stocks divide into $75,000 × 0.70 = $52,500 US and $75,000 × 0.30 = $22,500 international. Change the age, the portfolio, or the rule, and the calculator re-splits the whole portfolio.
The worked example, line by line
Setup: age 35; portfolio value $100,000; rule 110 minus age.
Line 1 — the stock percentage. 110 − 35 = 75%.
Line 2 — the bond percentage. 100% − 75% = 25%.
Line 3 — the stock dollars. $100,000 × 0.75 = $75,000.
Line 4 — the US stocks. $75,000 × 0.70 = $52,500.
Line 5 — the international stocks. $75,000 × 0.30 = $22,500.
Line 6 — the bonds. $100,000 × 0.25 = $25,000.
Line 7 — the other rules at the same age and value. 100 minus age gives 65% stocks, $65,000 (US $45,500 / international $19,500), bonds $35,000. 120 minus age gives 85% stocks, $85,000 (US $59,500 / international $25,500), bonds $15,000. The glide path gives 90% stocks, $90,000 (US $63,000 / international $27,000), bonds $10,000.
Every branch, checked
Age 25, $50,000, 110 minus age: stocks are 110 − 25 = 85%, or $42,500 (US $29,750 / international $12,750), and bonds are $7,500. At 25 the portfolio is nearly all stocks, because forty years of compounding can absorb a crash.
Age 55, $250,000, 110 minus age: stocks are 110 − 55 = 55%, or $137,500 (US $96,250 / international $41,250), and bonds are $112,500. At 55 the portfolio is nearly balanced, because retirement is close enough that a big drawdown would hurt.
Age 65, $500,000, 110 minus age: stocks are 110 − 65 = 45%, or $225,000 (US $157,500 / international $67,500), and bonds are $275,000. At 65 bonds are the majority, because the portfolio has to fund spending now, not just grow.
Glide path at 65: the glide path gives 90 − 1.5 × (65 − 40) = 90 − 37.5 = 52.5% stocks, or $262,500 (US $183,750 / international $78,750), and bonds are $237,500. The glide path keeps more in stocks than 110 minus age does at 65, because it assumes a long retirement still needs growth.
Age 70, $500,000: 110 minus age gives 40% stocks, $200,000 (US $140,000 / international $60,000), and bonds $300,000. The glide path gives 90 − 1.5 × 30 = 45% stocks, $225,000 (US $157,500 / international $67,500), and bonds $275,000. The glide path bottoms out at 30% stocks, so it never goes as bond-heavy as the simple rules can.
Reverse — the age for a 60% stock target: under 110 minus age, 60% stocks means age 110 − 60 = 50. Under 100 minus age it means age 40, and under the glide path it means age 40 + (90 − 60) / 1.5 = 60. The same target implies a different age under each rule, because each rule glides at a different speed.
What the defaults assume
The rules are heuristics, not advice: 110 minus age, 100 minus age, and 120 minus age are rules of thumb that move the stock percentage one point per year of age. The glide path is 90% stocks up to age 40, then 90 − 1.5 × (age − 40) after that, floored at 30% — a simplified version of how target-date funds glide down. The stock split is always 70% US and 30% international, whatever the rule. Cash is not modelled: the portfolio is assumed to be fully invested in stocks and bonds. The model ignores risk tolerance, other income, pensions, taxes, and the fact that a retiree with a pension can afford more stocks than the rule suggests. Rebalance annually, or whenever any sleeve drifts more than 5 percentage points from its target. Rounding convention: percentages are shown to one decimal where needed and dollars are rounded to the nearest dollar, computed from unrounded values.
Output · formula · meaning
| Output | Formula | What it means |
|---|---|---|
| Stocks % | rule: 110, 100, or 120 − age; glide: 90% to 40, then 90 − 1.5 × (age − 40), floor 30% | 75% at the defaults. |
| Bonds % | 100% − stocks % | 25% at the defaults. |
| Stock dollars | portfolio × stocks % | $75,000 at the defaults. |
| US stocks | stock dollars × 70% | $52,500 at the defaults. |
| International stocks | stock dollars × 30% | $22,500 at the defaults. |
| Bond dollars | portfolio × bonds % | $25,000 at the defaults. |
| 100 minus age | 100 − 35 = 65% | 65% / $65,000 (US $45,500 / Intl $19,500), bonds $35,000. |
| 120 minus age | 120 − 35 = 85% | 85% / $85,000 (US $59,500 / Intl $25,500), bonds $15,000. |
| Glide path | age ≤ 40 → 90% | 90% / $90,000 (US $63,000 / Intl $27,000), bonds $10,000. |
| Age 25, $50,000 | 110 − 25 = 85% | 85% / $42,500 (US $29,750 / Intl $12,750), bonds $7,500. |
| Age 55, $250,000 | 110 − 55 = 55% | 55% / $137,500 (US $96,250 / Intl $41,250), bonds $112,500. |
| Age 65, $500,000 | 110 − 65 = 45% | 45% / $225,000 (US $157,500 / Intl $67,500), bonds $275,000. |
| Glide at 65 | 90 − 1.5 × 25 = 52.5% | 52.5% / $262,500 (US $183,750 / Intl $78,750), bonds $237,500. |
| Age 70, $500,000 | 110 − 70 = 40%; glide 45% | 40% / $200,000, bonds $300,000; glide 45% / $225,000, bonds $275,000. |
| Reverse: 60% stocks | solve each rule for age | Age 50 (110-age); 40 (100-age); 60 (glide). |
Who uses this
- The 35-year-old with a first $100,000: learns the 110-minus-age rule gives 75% stocks ($75,000) and 25% bonds ($25,000) — so the portfolio is growth-heavy but not all-in, and the $52,500 US / $22,500 international split is the starting point.
- The 25-year-old just starting: learns the rule gives 85% stocks on a $50,000 portfolio — so nearly everything rides on stocks, and a 40% crash is a buying opportunity, not a disaster, with forty years ahead.
- The 55-year-old five years from retirement: learns the rule gives 55% stocks ($137,500) on $250,000 — so the portfolio is nearly balanced, and the $112,500 in bonds is the cushion that funds the first years of retirement.
- The 65-year-old choosing a glide path: learns the glide path keeps 52.5% in stocks ($262,500) against 45% under 110 minus age — so the target-date approach stays growthier in retirement, and the choice is really about how much risk the retiree can sleep with.
Accuracy & limitations
The arithmetic is exact for the numbers you enter: the stock percentage comes straight from the chosen rule, bonds are the remainder, and the US/international split is always 70/30 of the stocks. The glide formula is 90% stocks at age 40 or younger, falling 1.5 points a year after that, never below 30%. What is not exact is the advice: these are rules of thumb, and the right allocation also depends on your risk tolerance, your pension or Social Security income, your spending needs, your taxes, and whether you can leave the money alone in a crash. A retiree with a generous pension can hold more stocks than the rule says; a saver with no other income may need more bonds. This calculator is a starting point for thinking, not a personal recommendation. Rebalance annually or when any sleeve drifts more than 5 percentage points from its target.
Cite this calculatorBright Side Kit. “Asset Allocation by Age Calculator: Stocks vs Bonds.” brightoolbox.com, 2026. Method: stocks % from the chosen rule — 110 minus age, 100 minus age, 120 minus age, or the target-date glide path (age ≤ 40 → 90%; age > 40 → max(30, 90 − 1.5 × (age − 40))); bonds % = 100 − stocks %; stocks split 70% US / 30% international. Defaults: age 35, $100,000, 110 minus age → 75% stocks $75,000 (US $52,500 / Intl $22,500), bonds 25% $25,000; 100 minus age → 65% $65,000 (US $45,500 / Intl $19,500), bonds $35,000; 120 minus age → 85% $85,000 (US $59,500 / Intl $25,500), bonds $15,000; glide → 90% $90,000 (US $63,000 / Intl $27,000), bonds $10,000; age 25 $50,000 → 85% $42,500 (US $29,750 / Intl $12,750), bonds $7,500; age 55 $250,000 → 55% $137,500 (US $96,250 / Intl $41,250), bonds $112,500; age 65 $500,000 → 45% $225,000 (US $157,500 / Intl $67,500), bonds $275,000; glide at 65 → 52.5% $262,500 (US $183,750 / Intl $78,750), bonds $237,500; age 70 $500,000 → 110 minus age 40% $200,000 (US $140,000 / Intl $60,000), bonds $300,000; glide 45% $225,000 (US $157,500 / Intl $67,500), bonds $275,000; reverse: 60% stocks → age 50 (110 minus age), 40 (100 minus age), 60 (glide). Rebalance annually or when any sleeve drifts more than 5 percentage points. No external data needed — all math is from the inputs.
Bright Side Kit. "Asset Allocation by Age Calculator: Stocks vs Bonds" https://brightoolbox.com/asset-allocation-by-age-calculator/ Accessed October 24, 2026.Frequently asked questions
What does 110 minus age actually mean?
It means your stock percentage is 110 minus your age. At 35, stocks are 110 − 35 = 75% and bonds are 25%. At 65, stocks are 45% and bonds are 55%. The rule drops your stock share one point a year as you age, because you have less time to recover from a crash.
Why is the glide path different from 110 minus age?
Because it starts higher and falls more slowly. The glide path holds 90% stocks until age 40, then falls 1.5 points a year, floored at 30%. At 65 it gives 52.5% stocks against 45% for 110 minus age, and at 70 it gives 45% against 40%. Target-date funds glide this way because a 30-year retirement still needs growth.
Why split stocks 70% US and 30% international?
It is a simple home-bias split: most of the money stays at home, some owns the rest of the world. At the defaults, $75,000 in stocks becomes $52,500 US and $22,500 international. The exact split is a choice, not a law — what matters is owning both, so one market’s bad decade is not your whole portfolio.
Should I really be 85% in stocks at 25?
The rule says yes, and the logic is time. At 25, $50,000 at 85% stocks is $42,500 in stocks and $7,500 in bonds, and a 40% crash costs about $17,000 — painful, but with forty years of contributions ahead it is recoverable. The bigger risk at 25 is not volatility but not investing enough.
What if I am more cautious than the rule?
Use the 100-minus-age rule instead, or the glide path with a lower floor. At 35, 100 minus age gives 65% stocks ($65,000) and $35,000 in bonds, a calmer portfolio than the 75% the 110 rule gives. The right allocation is the one you can hold through a crash without selling — a rule you abandon in a panic is worse than a conservative rule you keep.
When do I rebalance?
Annually, or when any sleeve drifts more than 5 percentage points from its target. Stocks grow faster than bonds, so left alone the portfolio drifts stock-heavy: a 75/25 split can become 80/20 after a good few years. Selling some stocks and buying bonds back to target is the discipline that keeps the allocation honest.
Does the rule change if I have a pension?
Yes — a pension is like owning bonds already. If a pension or Social Security covers your spending, you can afford more stocks than the rule suggests, because your income does not depend on the portfolio. The rule assumes the portfolio has to do all the work; adjust up if other income does some of it.
Is 45% stocks at 65 too much, or too little?
It depends on how long the money has to last. At 65 with $500,000, 110 minus age gives 45% stocks ($225,000) and $275,000 in bonds, while the glide path gives 52.5% ($262,500). A 65-year-old may live another 25–30 years, so the portfolio still needs growth — going all bonds at retirement is its own risk, the slow one of inflation.