How Long Should a Diabetic Foot Ulcer Take to Heal, and When Is It Time for Surgery?

November is American Diabetes Month, and a slow-healing ulcer is a common worry. This guide is about the clock: normal healing time, how to tell whether an ulcer is on track, and when the plan should change. For the reasons an ulcer stalls, see why diabetic foot ulcers don’t heal.

How long does a diabetic foot ulcer take to heal?

It depends on the ulcer. Across studies, about 30% to 40% of diabetic foot ulcers heal by 12 weeks.⁠^[5] Three study groups show how wide the range is.⁠^[2,1]

In the larger consortium study, 4% of people had an amputation by week 12 and 10% by week 32.⁠^[1]

Three things set the pace: the ulcer’s size, how long it has been open and how deep it goes. In more than 31,000 people with nerve-related ulcers, all three were linked with whether the wound healed by week 20.⁠^[6] In the consortium data, area and duration predicted healing too.⁠^[1] The English clinic saw ulcers early, a median of 15 days after they started, and its authors stressed early expert assessment.⁠^[2]

Diabetic foot ulcer healing stages

Every wound heals in four phases: stopping the bleeding, inflammation, rebuilding (proliferation) and remodeling.⁠^[7]

• Inflammation, usually several days. White blood cells clear debris and germs.⁠^[8]
• Rebuilding, which can last several weeks. Granulation tissue, a new base of healing tissue, fills the wound, new blood vessels form and new skin covers the surface.⁠^[8]
• Remodeling. The new tissue matures and gains strength.⁠^[8]

Diabetes is one of the factors that can disrupt these phases.⁠^[7] A chronic ulcer has stalled along the way, and the work is finding what holds it back.

How do you know if a diabetic foot ulcer is healing?

Measure it. We record the length, width and depth at visits; see wound care visits.

The 4-week mark is the clearest early signal:

• In a trial of 203 people, ulcers that went on to heal had shrunk by 82% on average at 4 weeks; those that didn’t had shrunk by 25%.⁠^[9]
• In two more trials’ standard-care groups, ulcers that shrank by half or more by week 4 healed by week 12 in 57% and 52% of cases. Those that shrank less healed in 5% and 2%, whatever their starting size.⁠^[3]
• In an analysis of 241 diabetic foot ulcers from two trials, ulcers that had made little progress by week 4 were very likely to still be open 8 weeks later.⁠^[10]

The 4-week decision point

The ADA’s 2026 Standards of Care list five basics of ulcer care: offloading pressure, debridement (removing dead tissue and callus), restoring blood flow when needed, treating infection and the right dressing.⁠^[11] If a wound hasn’t shrunk by 50% after 4 weeks of that care, the ADA says to consider advanced wound therapy. It also says a stalled ulcer needs a check for a deformity that surgical offloading should correct, and for bone infection.⁠^[11]

The vascular guideline also advises rechecking circulation and consulting a vascular specialist when an ulcer shrinks less than 50% in 4 weeks despite good care.⁠^[12]

When is it time for surgery?

When the 4-week check shows a stall, an operation can remove the cause directly.

• Pressure that a cast or boot can’t relieve. If non-surgical offloading fails to heal an ulcer under the ball of the foot, the guideline advises considering Achilles tendon lengthening, metatarsal head resection, joint arthroplasty or a metatarsal osteotomy. For a toe ulcer from a flexible bent toe, it advises a flexor tenotomy (toe tendon release).⁠^[13] After tenotomy, 97% of toe ulcers healed, in about 30 days on average.⁠^[14] See offloading surgery and the Center for Lower Extremity Surgery’s page on a related calf release, gastrocnemius recession (external site).
• Bone under the ulcer. In the randomized trial of 42 people with uninfected nerve-related ulcers, removing the ulcer, any bone beneath it when needed, and closing the wound healed 95.5% of ulcers against 79.2% with standard care, in about a third of the time, with fewer infections and relapses.⁠^[4]
• Dead tissue and callus. The guideline advises debridement, preferably with sharp surgical instruments, repeated as needed.⁠^[15]
• Infection in the bone. Bone infection has to be ruled out in an ulcer that won’t heal and treated with surgery, antibiotics or both.⁠^[11] See osteomyelitis surgery.
• A large, clean wound. Once the wound bed is healthy, a skin graft or local flap can close it. See skin grafts and flaps.
• Poor blood flow. When an ulcer shows no sign of healing in 4 to 6 weeks, the guideline advises considering imaging of the arteries and a procedure to restore flow.⁠^[15] We refer you to a vascular specialist and time your foot surgery around it.

Dr. Efe Ozturk, a Foot and Ankle Surgeon who is double board certified, including in wound care (FAPWH), performs Achilles lengthening, toe tendon release, metatarsal head resection, bone surgery, skin grafts and flaps, and surgical debridement. Wound VAC therapy and skin substitutes are also available when they fit, and when hyperbaric oxygen might help, we refer you.

Limits

Healing figures differ a lot between groups of patients, as the table shows, and they are averages that can’t predict one wound.⁠^[1,2] The 4-week findings come from standard-care patients in trials, analyzed afterward.⁠^[3] The surgery trial was small and older, and included only uninfected ulcers.⁠^[4] Not every operation speeds healing: in a trial of Achilles lengthening, ulcers healed at a similar pace with or without it, and the benefit was fewer ulcers coming back.⁠^[16] A healed ulcer also isn’t the finish line: recurrence is estimated at 42% within a year.⁠^[5]

Common questions

How do you know if a diabetic foot ulcer is healing?

It gets measurably smaller. An ulcer that has shrunk by half or more after 4 weeks of good care is on track; less than that is the signal to change the plan.⁠^[3,11]

What are the stages of diabetic foot ulcer healing?

Inflammation over several days, then rebuilding with granulation tissue and new skin, which can take several weeks, then remodeling as the new tissue gains strength.⁠^[8]

What if a diabetic foot ulcer hasn’t healed in 12 weeks?

Many still heal: in the consortium study, healing rose from 26% at 12 weeks to 49% at 32 weeks.⁠^[1] But a wound that made poor progress by week 4 is likely to still be open at week 12,⁠^[10] so it deserves a full re-evaluation and a surgical opinion.

Does surgery make a diabetic foot ulcer heal faster?

It can. In the randomized trial, surgery healed ulcers in about 47 days on average, against about 129 days with standard care.⁠^[4] Achilles lengthening mainly prevents the ulcer from coming back.⁠^[16]

The bottom line

A diabetic foot ulcer usually takes months to heal, and the 4-week mark is your clearest early signal. If it hasn’t shrunk by about half, don’t wait out another month on the same plan. Ask for a fresh look at pressure, blood flow, infection and bone, and a surgical opinion on the operation that could fix the cause.