Concrete cure time calculator
Pick the type of concrete and the average air temperature over the next week to see how long to keep it curing and when it reaches its milestones. Every figure here comes from a manufacturer data sheet or NRMCA.
Enter your measurements
- Setting
- Sets and hardens within about 2–8 hours of mixing (NRMCA)
- First loads
- Posts and light loads after 24 hours (Quikrete Concrete Mix)
- Strength gain
- ≈ 2,500 psi at 7 days, 4,000 psi at 28 days (Quikrete Concrete Mix lab figures)
- Freezing
- Protect from freezing for at least 48 hours (Quikrete); NRMCA: until it reaches 500 psi, about two days after placing
- For this temperature
- Warm weather. Quikrete calls for 5 days of curing at 70 °F or above. Keep the surface from drying out in sun and wind.
70 °F: at or above 70 °F → 5 days (Quikrete)
Mix: Standard mix — Posts and light loads after 24 hours (Quikrete Concrete Mix)
- These are the earliest points the sources give, under the conditions they assume. Heavier loads, vehicles and structural use need the strength your plans or supplier specify — ask them.
Quick answers for common sizes
| Example | Answer |
|---|---|
| How long before you can walk on concrete | 4 hours for fast-setting mix; about a day for standard concrete |
| How long before you can drive on concrete | Cars after about 7 days; heavy trucks after 28 days or when your supplier confirms |
| Can you pour concrete in cold weather | Yes, if it is protected from freezing until about 500 psi (about 2 days) |
Curing days and guidance by temperature
| Average air temperature for the next week | Moist-cure for | For this temperature |
|---|---|---|
| 35 °F | 7 days | Cold weather by ACI’s definition (air at or below 40 °F during the protection period). Protect the concrete from freezing (insulated blankets, heated enclosures) until it reaches about 500 psi, and keep it above 50 °F to keep curing. Consider waiting for a warmer spell or asking the ready-mix plant for a cold-weather mix. |
| 45 °F | 7 days | Below 50 °F: setting and strength gain slow down — NRMCA notes a 20 °F drop roughly doubles setting time. Keep the concrete above 50 °F while it cures if you can, and don’t use curing compounds if it will drop below 50 °F within 24 hours (Quikrete). |
| 55 °F | 7 days | Mild weather. Quikrete calls for 7 days of curing between 50 °F and 70 °F. |
| 65 °F | 7 days | Mild weather. Quikrete calls for 7 days of curing between 50 °F and 70 °F. |
| 75 °F | 5 days | Warm weather. Quikrete calls for 5 days of curing at 70 °F or above. Keep the surface from drying out in sun and wind. |
| 95 °F | 5 days | Hot weather: concrete sets faster and dries out sooner. NRMCA advises curing for at least 3 days and not adding water to concrete more than 1½ hours old; start curing as soon as finishing is done. |
Concrete doesn’t dry hard — it hardens because cement reacts with water, and that reaction needs both moisture and warmth. Curing means keeping fresh concrete damp and above about 50 °F long enough for that reaction to build strength. NRMCA’s curing guide says to continue it typically 3 to 7 days, and warns that concrete left to dry out can lose as much as half its potential strength.
Cure time chart
| Milestone | Standard mix | Fast-setting mix | Source |
|---|---|---|---|
| Sets / hardens | about 2–8 hours after mixing | 20–40 minutes | NRMCA CIP 31; Quikrete 1004 |
| Light use | posts loaded after 24 hours | walk on, load posts after 4 hours | Quikrete 1101 and 1004 |
| Protect from freezing | at least 48 hours / until 500 psi | at least 48 hours | Quikrete; NRMCA CIP 27 |
| Keep curing (≥ 70 °F) | 5 days | 5 days | Quikrete |
| Keep curing (50–70 °F) | 7 days | 7 days | Quikrete |
| Strength at 7 days | ≈ 2,500 psi (of 4,000) | ≈ 2,500 psi (of 4,000) | Quikrete lab figures |
| Design strength | 28 days | 28 days | Quikrete; ACI acceptance testing |
| De-icing salts | avoid in the first winter | avoid in the first winter | NRMCA CIP 2 |
Common questions, worked through
- How long before you can walk on concrete — and why it depends on the mix.
- How long before you can drive on concrete — curing, strength and waiting for your supplier’s number.
- Can you pour concrete in cold weather — NRMCA’s definition and what protection looks like.
How to cure concrete
- Curing compound. Spray or roll a compound such as an acrylic cure & seal once the surface is hard enough; Quikrete applies its product at 200 sq ft per gallon as a curing compound.
- Plastic sheeting. Lay it flat, seal the joints and weigh the edges. NRMCA calls for sheeting at least 4 mils thick. It can blotch coloured concrete.
- Water. Wet burlap or a sprinkler that keeps the surface continuously wet. Letting it dry between soakings defeats the purpose.
Penn State’s concrete course notes, drawn from PCA’s Design and Control of Concrete Mixtures, put the minimum at 7 days or until 70% of the specified strength, and 3 days for high-early-strength concrete above 50 °F. The calculator follows Quikrete’s data sheets for its own products and shows NRMCA’s range alongside.
What you’ll need
- Acrylic concrete cure and sealMid-range price
Rolled or sprayed onto fresh concrete, it holds moisture in while the slab cures and leaves a light sealed finish.
See options on Amazon (opens in a new tab) - Poly vapor barrier sheetingBudget price
Plastic sheeting under an indoor slab, and over a fresh slab to hold moisture in while it cures.
See options on Amazon (opens in a new tab) - Pump sprayerBudget price
Applies cure-and-seal and penetrating sealers evenly. Check the sealer label for a solvent-resistant sprayer if needed.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How long does concrete take to fully cure?
Concrete keeps gaining strength for months, but design strength is measured at 28 days — Quikrete’s and ACI’s reference age. Active curing (keeping it moist) is needed for the first 5–7 days per Quikrete, or 3–7 days per NRMCA.
Can it rain on new concrete?
Once the surface has hardened, rain helps curing. Rain on concrete that hasn’t set can wash out the surface; cover it with plastic if rain is coming in the first few hours. Quikrete says not to apply curing compound if rain is expected within 24 hours.
When can I seal new concrete?
A cure-and-seal product goes on as soon as the surface is hard. For other sealers, the label says how long the concrete must cure first. See the sealer calculator.
Does concrete cure faster in hot weather?
It sets faster, but it also dries out faster, which can leave a weaker, crack-prone surface. NRMCA advises curing for at least 3 days in hot weather and starting as soon as finishing is done.
Related guides
Sources
- Quikrete Concrete Mix (No. 1101) data sheet (opens in a new tab) — Yields: 40 lb ≈ 0.30, 50 lb ≈ 0.375, 60 lb ≈ 0.45, 80 lb ≈ 0.60, 90 lb ≈ 0.675 cu ft; unit weight ≈ 140 lb/cu ft; for pours 2 in thick or more; 6–9 pints of water per 80 lb bag; control joints every 6–8 ft; cure 5 days at 70 °F or above, 7 days at 50–70 °F; protect from freezing for 48 hours.
- Quikrete Fast-Setting Concrete Mix (No. 1004) data sheet (opens in a new tab) — 50 lb ≈ 0.375 cu ft, 60 lb ≈ 0.45 cu ft, 25 kg ≈ 11.6 L, 30 kg ≈ 14 L; sets in 20–40 minutes; post holes 3× the post width and ⅓ of the post length deep; wait 4 hours before loading a post.
- Quikrete 5000 Concrete Mix (No. 1007) data sheet (opens in a new tab) — 60 lb ≈ 0.45, 80 lb ≈ 0.60 cu ft; ≈ 140 lb/cu ft; 1,500 psi at 1 day, 2,500 at 3, 3,500 at 7 and 5,000 at 28 days; 2 in minimum thickness.
- NRMCA Concrete in Practice 11 — Curing In-Place Concrete (opens in a new tab) — Cure for typically 3 to 7 days; keep placed concrete above 50 °F (10 °C); concrete in a dry environment can lose as much as 50% of its potential strength.
- American Concrete Institute — ACI 306R-16 Guide to Cold Weather Concreting (preview) (opens in a new tab) — Cold weather: when air temperature has fallen to, or is expected to fall below, 40 °F (4 °C) during the protection period.
- NRMCA Concrete in Practice 2 — Scaling Concrete Surfaces (opens in a new tab) — Order air-entrained concrete (about 6% air) for exterior slabs exposed to freezing and de-icers; avoid de-icing chemicals in the first winter.
- City of Redmond, WA — Concrete crew FAQ (opens in a new tab) — A minimum of 7 days before passenger cars on new concrete; heavy loads not until 28 days.
- NRMCA Concrete in Practice 27 — Cold Weather Concreting (opens in a new tab) — Cold weather definition; protect from freezing until 500 psi, about two days; a 20 °F drop roughly doubles setting time.
- NRMCA Concrete in Practice 12 — Hot Weather Concreting (opens in a new tab) — Continue curing for at least 3 days; avoid adding water to concrete more than 1½ hours old.
- NRMCA Concrete in Practice 31 — Ordering Ready Mixed Concrete (opens in a new tab) — Truck mixers carry 8 to 12 cubic yards (about 6 to 9 m³); order 4–10% more than the plan estimate; a loaded truck weighs about 80,000 lb; fresh concrete can cause severe chemical burns.
- Penn State CE 584 — Curing (compiled from Kosmatka et al., PCA Design and Control of Concrete Mixtures) (opens in a new tab) — Cure at least 7 days (above 40 °F) or until 70% of specified strength; 3 days for high-early-strength concrete above 50 °F; air-dried concrete gains only about 50% of the strength of moist-cured.
- American Concrete Institute — FAQ: why is compressive strength tested at 28 days? (opens in a new tab) — Specified compressive strength is based on 28-day test results; 3- and 7-day results are not commonly used for acceptance.