How Release Dates Are Calculated in Colorado

If you or someone you love is doing time in Colorado, the release date math starts with one key number: 50 percent of the sentence. For most felonies, that is when a person first becomes eligible for parole, and earned time credits can pull that date in even earlier. But eligibility is not release; the State Board of Parole decides whether to grant parole, and that decision is discretionary.

This guide walks through how Colorado calculates a release date step by step: the 50 percent parole eligibility base and how earned time reduces it, the higher thresholds for serious violent crimes, the recent 2024 violent crime parole changes and Proposition 128, and the mandatory release rule that applies when the board does not act. None of this is legal advice, but it will help you read your own time the way the Department of Corrections does.

Here is the short version.

For most Colorado felonies, parole eligibility arrives at 50 percent of the sentence imposed, less earned time credits that can reduce the sentence by up to 30 percent. So the earliest parole eligibility date can be as little as 20 percent of the sentence. The State Board of Parole then decides release discretionarily. Serious violent crimes have a higher threshold, currently 85 percent with no earned time reductions for offenses committed on or after July 1, 2024, and a full sentence for repeat violent offenders. If the board has not granted parole, mandatory release applies when earned time has reduced the sentence by 25 percent.

Step one: the 50 percent base and how it works

Colorado uses determinate sentencing, meaning the court sets a specific number of years. The sentence drives the calculation, and parole eligibility is built off that number.

For most felonies, classes 2 through 6 and unclassified felonies, the Parole Eligibility Date is set at 50 percent of the sentence imposed, less any earned time credits and any time credited for presentence confinement. The Department of Corrections calculates this date using the sentence, the credits, and the applicable statutes. The result is the earliest date a person can apply for parole, not the date they will actually be released.

It is worth knowing that Colorado abolished traditional good time many years ago and replaced it with this automatic 50 percent base. So lawyers and family members may sometimes use the phrase good time loosely, but what it means in practice today is the 50 percent calculation and the earned time system that sits on top of it.

Step two: earned time and how it moves the date

Earned time is the tool that can pull the Parole Eligibility Date in from the 50 percent base.

Under Colorado statute, earned time is credited at up to ten days per month of incarceration. The total earned time that can be applied to reduce the sentence is capped at 30 percent of the sentence. With maximum earned time, a person's Parole Eligibility Date can move from 50 percent of the sentence down to as early as 20 percent, because the 50 percent base is reduced by up to 30 percentage points of earned time.

Earned time is reviewed annually while a person is incarcerated and twice a year while on parole, and it vests after review. It can be reduced or lost for misconduct. Colorado also allows Achievement Earned Time, which is an additional layer: up to 60 days per completed milestone, phase of a program, or instance of exceptional conduct, with a cap of 120 days total from this source. These extra days come on top of the standard monthly earned time and can push the Parole Eligibility Date even earlier than the standard calculation would produce.

The key point is that earned time is earned, not automatic. A person who follows the rules, participates in programs, and earns achievement credits can see real movement in their Parole Eligibility Date, while someone who loses earned time for misconduct will see the date move the other way.

Step three: the violent crime thresholds

Colorado has higher parole eligibility thresholds for serious violent crimes, and the rules changed significantly in 2024.

For serious violent offenses committed before July 1, 2024, the parole eligibility threshold rises to 75 percent of the sentence, with credit for earned time. This covers a specific list of offenses under the statute, and it means a much larger share of the sentence must be served before parole eligibility arrives.

For offenses committed on or after July 1, 2024, Colorado enacted a law creating a new 85 percent threshold for a specific list of crimes: second degree murder, first degree assault, class 2 felony kidnapping, sexual assault, first degree arson, first degree burglary, and aggravated robbery. For these offenses at the 85 percent tier, earned time does not reduce the threshold. And for a person who has twice previously been convicted of a crime of violence, the rule is one hundred percent, meaning the full sentence must be served before parole can begin. Proposition 128, passed by Colorado voters in November 2024 and effective for offenses committed on or after January 1, 2025, extended the same 85 percent and one hundred percent structure going forward.

So the threshold that applies depends on the offense and when it was committed. Most offenses still fall under the standard 50 percent base with earned time. The 75 percent, 85 percent, and one hundred percent tiers apply to specific serious violent crimes at specific offense dates.

Step four: mandatory release if parole is not granted

If the State Board of Parole has not granted discretionary parole, Colorado has a mandatory release provision that kicks in near the end of the sentence.

Colorado limits the total earned time that can reduce the sentence for mandatory release purposes to 25 percent. This means that even if parole is not granted, a person is mandatorily released when they have served the sentence minus 25 percent earned time, which works out to serving 75 percent of the sentence. At that point, the person is released to parole supervision to serve the remainder of the sentence in the community.

This backstop matters because it means that in practice most people serving standard sentences do not serve the full sentence in prison, even if the board repeatedly declines to grant discretionary parole. The mandatory release date acts as a hard floor below which the sentence cannot be reduced, and the person leaves prison on supervision regardless.

Step five: sex offenders, life sentences, and special cases

Not everyone is on the standard 50 percent track, and a few categories have significantly different calculations.

Colorado enacted the Sex Offender Lifetime Supervision Act for class 4 and more serious felony sex offenses. Under this law, a person receives an indeterminate sentence with life as the maximum and a court set minimum as the floor. The minimum determines the Parole Eligibility Date. At that date, the parole board evaluates whether the person is suitable for release, with sex offender treatment progress being central to the decision. If released, the person is on parole supervision for life with ongoing treatment and monitoring requirements.

People serving life sentences for crimes such as first degree murder have their own parole eligibility rules, typically requiring service of a long minimum before the board can consider release. The standard 50 percent calculation and the earned time cap do not apply to life sentences in the same way. Anyone serving a life term should confirm the applicable rules with the Department of Corrections, because the statutes governing life sentences operate differently from the standard class felony framework.

Putting it together: a worked example

Here is how the pieces fit, using a simple example. None of these numbers are legal advice, but they show the method.

Say a person is sentenced to ten years for a standard class felony with no violent crime override. The Department calculates the 50 percent base, which is five years. Earned time is credited at up to ten days per month. Over the sentence, maximum earned time could reduce the date by up to 30 percent of the ten years, or three years, moving the Parole Eligibility Date as early as two years into the sentence. In practice, Achievement Earned Time for program completions and exceptional conduct can push it a bit further still. The State Board of Parole then reviews the case at or after the Parole Eligibility Date and decides whether to grant parole. If it does not, and the person has served the sentence minus 25 percent earned time, mandatory release kicks in at the 75 percent mark, or seven and a half years.

Now change the offense to aggravated robbery committed in 2025. The 85 percent threshold applies, and earned time does not count toward it. The Parole Eligibility Date is at 85 percent of the ten years, or eight and a half years, with no earned time offset. If that person also had two prior violent convictions, the threshold is one hundred percent and the full sentence must be served before parole begins. Same ten years on paper, very different time served.

The bottom line for Colorado

Colorado release dates come down to the sentence, the violent crime tier, and earned time. For most felonies the Parole Eligibility Date is 50 percent of the sentence, reduced by earned time up to 30 percent, so the earliest eligibility can be around 20 percent of the sentence. The State Board of Parole then decides discretionary release. Serious violent crimes carry higher thresholds: 75 percent with earned time for older offenses, 85 percent with no earned time offset for offenses since July 1, 2024, and one hundred percent for repeat violent offenders.

The practical takeaways are clear. First, identify the offense class and the date of the offense, because they set the parole eligibility threshold. Second, earn time through programs and good conduct, because each earned day directly moves the Parole Eligibility Date. Third, understand that mandatory release at 75 percent of the sentence is the backstop if the board does not grant parole. Ask the Department of Corrections for your time computation sheet to see your Parole Eligibility Date, your earned time balance, and your mandatory release date.