Last updated: 5 September 2026

Sims 4: How to Age Up — All Life Stages

Aging in The Sims 4 can feel either too fast or frustratingly stuck, depending on what you want. This guide covers every way to age a Sim up — cakes, cribs, and cheats — walks through all eight life stages, and shows how to control the lifespan so your family ages at exactly the pace you like.

01The Eight Life Stages

Sims progress through eight stages, each lasting a set number of days on the normal lifespan:

1. Newborn — the bassinet stage, fully dependent on adults.
2. Infant — crawling stage with its own skills and needs.
3. Toddler — walking and talking; builds toddler skills.
4. Child — school, child skills, and aspirations.
5. Teen — part-time jobs and teen social life.
6. Young Adult — the prime stage for careers and family.
7. Adult — continues careers; aging starts to show.
8. Elder — the final stage, ending eventually in death by old age.

Exact day lengths per stage depend on your lifespan setting and can change with patches — check the values in your own game.

02Aging Up With a Birthday Cake

The classic, no-cheat way to age up is a birthday celebration:

1. Use an oven or stove → Cook → Cake (or buy a cake from Build/Buy).
2. Click the finished cake → Add Birthday Candles.
3. Have the Sim Blow Out Candles — they age up to the next stage with a small celebration.
4. For babies and toddlers who cannot do it alone, an adult selects 'Help Blow Out Candles' / Age Up for them.

Cake age-ups give a happy 'Birthday' moodlet. You can also throw a Birthday Party event for guests and rewards, but a simple cake is all you need.

03Aging Up From the Crib & High Chair

Newborns, infants and toddlers have a faster option that does not need a cake:

• Newborn / Infant: click the bassinet or crib → More Choices → Age Up.
• Toddler: the same Age Up option appears once they are ready to advance.
• This is the quickest legit way to move very young Sims along without baking.
• A Sim must usually be near the end of their current stage for the Age Up option to appear without cheats.

04Aging Up With Cheats

If you want to skip the wait entirely, cheats handle it. Open the console (Ctrl+Shift+C) and type testingcheats true first — there's no standalone typed command like 'sims.age_up' that works on its own; both instant methods below need testingcheats on first:

• Quick Age Up: with cheats enabled, Shift+Click the Sim and choose Age Up (sometimes labelled 'Trigger Age Transition') from the pie menu — this instantly advances them to the next life stage.
• CAS route: type cas.fulleditmode after testingcheats true, then Shift+Click the Sim → Modify in CAS and drag the age slider — useful for fine control or to make a Sim younger, which the pie-menu Age Up option cannot do.
• Cheating the age does not harm the save, but enabling cheats disables achievements for that session.

05Controlling Lifespan & Stopping Aging

If Sims are aging too fast — or you want them frozen — change the lifespan globally:

• Game Options → Gameplay: set lifespan to Short, Normal, or Long, or toggle auto-aging off entirely.
• You can disable aging for the played household only, or for unplayed households too, separately.
• Long lifespan is popular for Legacy and storytelling saves where you want time to play out each stage.
• Reward-store traits like Long Lived extend a single Sim's lifespan without changing the global setting.