2027 Social Security COLA Calculator: Estimate Your Monthly Benefit Increase

Updated September 15, 2026: The 2027 Social Security cost-of-living adjustment (COLA) has not been officially announced yet. The latest forecast from The Senior Citizens League, released September 11, projects a 3.5% COLA. That estimate is based on the inflation data available so far, including the August 2026 CPI-W reading. The Social Security Administration will make the official determination after September inflation data are released in October.

If you want a quick estimate now, multiply your current monthly Social Security benefit by 3.5%. For example, a $2,000 monthly benefit would increase by about $70, producing an estimated new benefit of about $2,070 before Medicare premiums, taxes, offsets, or other deductions. Because the official COLA is still pending, treat every 2027 amount below as an estimate rather than a confirmed payment.

2027 Social Security COLA calculator

For a simple planning estimate, use this formula:

Estimated monthly increase = current gross monthly benefit × projected COLA percentage

Estimated new monthly benefit = current gross monthly benefit + estimated monthly increase

Using the current 3.5% forecast, the shortcut is to multiply your benefit by 0.035 to estimate the increase, or by 1.035 to estimate the new gross benefit.

This table is useful for budgeting, but it is not an exact SSA benefit computation. Social Security explains that the COLA is applied to a beneficiary's primary insurance amount, or PIA, and that rounding rules, claiming-age adjustments, offsets, and deductions can cause the actual dollar increase to differ slightly from a simple percentage calculation. See the Social Security Administration's explanation of how a COLA is applied to a retirement benefit.

What is the latest 2027 COLA forecast?

As of September 15, 2026, the most recent widely cited forecast from The Senior Citizens League is 3.5%. The group issued that projection on September 11 after the Bureau of Labor Statistics released August inflation data. It was slightly lower than the group's 3.6% estimate in August and its 3.8% estimate in July.

The forecast is not the official Social Security COLA. It can still change because the final calculation depends on the complete third-quarter CPI-W data for July, August, and September. The Bureau of Labor Statistics reported that the CPI-W rose 3.5% over the 12 months ending in August 2026 and reached an index level of 328.481. The September CPI report is scheduled for October 14, 2026. You can verify the latest release at the Bureau of Labor Statistics August 2026 CPI release.

How Social Security actually calculates the 2027 COLA

The official COLA is not based on one month's year-over-year inflation rate. By law, the Social Security Administration compares the average CPI-W for the third quarter of the current year with the average CPI-W for the third quarter of the last year in which a COLA became effective. The result is rounded to the nearest one-tenth of one percent.

For the 2026 benefit increase, the third-quarter 2025 CPI-W average was 317.265, up from 308.729 in the third quarter of 2024, producing the official 2.8% COLA. Those figures and the calculation method are published by the Social Security Administration's COLA calculation page.

For the 2027 COLA, the relevant comparison will be the average CPI-W for July, August, and September 2026 against the third-quarter 2025 average of 317.265. That is why a forecast can move from month to month even when one headline inflation number appears stable.

What a 3.5% COLA could mean for your benefit

The dollar value of any COLA depends on the size of your benefit. A person receiving $1,500 per month would see a simple 3.5% estimate of $52.50 more per month, while someone receiving $3,000 would see about $105 more. Over 12 months, those approximate increases would be $630 and $1,260 respectively, assuming the benefit amount otherwise stayed unchanged.

The Senior Citizens League estimated in its September 11 forecast that a 3.5% COLA would raise a then-current average monthly benefit of $1,940.08 by about $67.90, to roughly $2,007.98. That example is a forecast-based illustration, not an official SSA estimate for January 2027. See the group's September 11, 2026 COLA forecast.

Try several scenarios instead of relying on one forecast

Because the official number is not known yet, a more useful budgeting approach is to test a small range. The table below shows what different COLA outcomes would mean for common benefit amounts.

This range is not a prediction of where the COLA will land. It is simply a planning tool that shows how sensitive your monthly increase is to the final percentage.

Why your bank deposit may rise by less than the headline COLA

The gross Social Security benefit and the amount deposited into your bank account are not always the same. If Medicare Part B premiums are deducted from your Social Security payment, a higher Medicare premium can absorb part of the COLA increase. Federal income tax withholding, benefit offsets, or other deductions can also affect the net payment.

In addition, SSA does not merely multiply the dollar amount shown on your last bank deposit by the COLA percentage. The agency applies the COLA through the benefit formula and then uses statutory rounding rules. That means a personal benefit may differ slightly from the simple calculator estimate shown here.

When will the official 2027 COLA be announced?

The Bureau of Labor Statistics has scheduled the September 2026 CPI release for October 14, 2026 at 8:30 a.m. Eastern Time. The Senior Citizens League says the Social Security Administration is expected to announce the official 2027 COLA that day once the third-quarter data are complete.

SSA's own COLA information currently confirms only that the latest official COLA is 2.8% for 2026 and that the next COLA will be announced in October 2026. For the authoritative status, check the Social Security Administration COLA page.

Which number should you enter in the calculator?

For the most practical estimate, use your current gross Social Security benefit before deductions, not the net amount deposited after Medicare or tax withholding. You can find your benefit information in your Social Security records or your COLA notice. If you use a bank deposit instead, your result may understate your actual gross benefit because deductions are already removed.

If your current gross benefit is $2,184, for example, a 3.5% planning estimate is:

$2,184 × 0.035 = $76.44 estimated monthly increase

$2,184 + $76.44 = $2,260.44 estimated monthly benefit

Your actual SSA amount may be a little different because of the PIA and rounding rules described above.

Bottom line

The best current estimate for the 2027 Social Security COLA is 3.5%, but it remains a forecast as of September 15, 2026. You can use 3.5% for a reasonable planning estimate today, while also checking a lower and higher scenario so your budget is not tied to one preliminary number. The official percentage will depend on September CPI-W data and is expected in October.

For now, multiply your current gross monthly benefit by 0.035 to estimate the monthly increase. Then revisit the calculation after the Social Security Administration publishes the official 2027 COLA.