Percentage Rent Increase Calculator

Find the percent change from old rent to new rent before you review a lease renewal or rent notice.

By The Calcumatix Team Reviewed by Calcumatix Editorial Review Updated July 9, 2026

Old rent ($)

New rent ($)

Result

+5%

Rent went from $2,000.00 to $2,100.00, a 5% increase

Quick Answer

Rent increase percentage is new rent minus old rent, divided by old rent, times 100, so a rise from 1,450 to 1,595 is ((1,595 - 1,450) / 1,450) x 100, which is 10 percent. The old rent is always the base. This calculator shows the size of a raise so you can compare it with local limits or prior increases.

How A Rent Increase Calculator Works, Step By Step

A percentage rent increase calculator shows how much rent changed compared with the old rent. Enter old rent and new rent for the same pay period, then the calculator subtracts old rent from new rent, divides by old rent, and turns the answer into a percent. Tenants and landlords use the result to compare lease offers, rent notices, and budget changes. The result can be positive, zero, or negative, so the sign shows whether rent rose, stayed flat, or fell. The calculator only shows the math, and it does not check rent caps, notice rules, lease rights, or local law.

Rent Increase Calculator: The Formula Behind The Result

Old rent is the rent before the change. New rent is the proposed or new rent. Compare the same pay period, such as monthly rent with monthly rent. Old rent must be greater than zero.

Rent increase percentage = ((new rent − old rent) ÷ old rent) × 100

Using The Rent Increase Calculator: Step By Step

Inputs

Old rent: rent before the change.
New rent: proposed or new rent.

Steps

Enter the old rent amount.
Enter the new rent amount.
Check that both values use the same pay period.
Read the rent increase percentage.
Review the lease and local rules before you act.

Rent Increase Calculator In Practice: A Real Example

Old rent = $1,450 and new rent = $1,595.

Rent increase percentage = ((1,595 − 1,450) ÷ 1,450) × 100.
1,595 − 1,450 = 145.
145 ÷ 1,450 = 0.1.
0.1 × 100 = 10, rounded to two decimal places = 10.00%.

The rent increase is 10.00%, rounded to two decimal places.

When To Use A Rent Increase Calculator (Or Not)

Use this rate when you compare a rent notice, a lease renewal, or a budget change. Keep the old rent, new rent, date, and lease notes with the result. The percent is easy to share, but the lease and local law decide what can happen next.

How To Review This Result Before A Business Change

Start with the rent period. Compare monthly rent with monthly rent, or weekly rent with weekly rent. Mixed periods will give a bad rate.

Keep a short lease note with the result. Write the notice date, old rent, new rent, and lease term. Do not use the percent as a legal test; check the lease and local rules, since rent caps and notice rules can change by place. See the business calculators hub for related tools.

Assumptions

Old rent is greater than zero.
Old rent and new rent use the same pay period.
Both inputs use the same currency.
The calculator measures percent change only.
The result rounds to two decimal places.

Limitations

The tool does not check rent caps.
Local rent law can vary by place and property type.
The result does not prove an increase is allowed.
Fees, tax, utilities, and discounts can change the full housing cost.

In Practice

The most common mistake is dividing by the new rent instead of the old rent, which makes the increase look smaller than it is. The starting rent is always the base for a change. Note too that local rent-control rules may cap the allowed rise, so a legal limit can matter as much as the math.

Year Over Year Percentage Calculator

Find year over year percent change for sales, cost, orders, traffic, or any metric with a prior and current value.

Open the Calculator

Ownership Percentage Calculator

Find raw ownership percentage from owned units and total units for shares, member units, co-op units, or partner units.

Open the Calculator

Related Guides

How To Calculate Occupancy Percentage For Hotel Rooms
Learn how to calculate occupancy percentage for hotels or property units, with the formula, Excel setup, worked example, and limits to check.
How To Calculate Overhead Percentage For Business Costs
Learn how to calculate overhead percentage using overhead cost and a chosen base, with accounting context, example, source checks, and limits.
How To Calculate Sales Percentage For Business Goals
Learn how to calculate sales percentage as sales-to-target or sales growth, with clear formulas, examples, Excel syntax, and business limits.
How To Calculate Shrinkage Percentage For Retail Loss
Learn how to calculate shrinkage percentage for retail inventory loss, with formula options, worked example, source context, and reporting cautions.
Calculate Pay Raise Percentage From Old And New Pay
Learn how to calculate pay raise percentage from old and new salary, with the percent-change formula, salary example, Excel setup, and pay limits.
Calculate Profit Or Margin Percentage In Excel For Business Use
Learn how to calculate profit or margin percentage in Excel with revenue, cost, profit formulas, percent formatting, and a checked business example for reports.

Frequently Asked Questions About Rent Increase Percent

How do you calculate rent increase percentage?

Rent increase percentage is new rent minus old rent, divided by old rent, then multiplied by 100. Compare the same pay period for both values.

Can the rent increase percentage be negative?

Rent increase percentage can be negative when new rent is lower than old rent. The negative sign shows that rent went down.

Does this calculator check rent control laws?

This calculator does not check rent control laws or local caps. Rules vary by place, property type, lease type, and notice date.

Should I include utilities or fees in rent?

Include utilities or fees only if you want to compare full housing cost. Leave them out if the lease lists rent as a separate line.

Why must old rent be greater than zero?

Old rent must be greater than zero because the formula divides by old rent. Zero gives the formula no valid base.

Sources

Reviewed for accuracy against the formula shown above.