GD Levels Chart: Your Exact Fasting, 1-Hour and 2-Hour Targets in mg/dL and mmol/L by Week

Medically reviewed by Sarah Tappan, RD, LD — Pregnancy Plate Planner editorial team

Here's the chart you came for, in both units, right at the top. For everyday gestational diabetes management, your targets are fasting under 95 mg/dL (under 5.3 mmol/L), 1 hour after a meal under 140 mg/dL (under 7.8 mmol/L), and 2 hours after a meal under 120 mg/dL (under 6.7 mmol/L). Those three numbers are the whole game. Everything else in this article is about how to read them, why they differ from the numbers on your diagnosis paperwork, and how to tell a problem reading from a one-off blip.

These come from the American Diabetes Association Standards of Care and are the same targets most US and Canadian providers use day to day. Want to double-check the target your provider actually uses (some use 1-hour testing, some use 2-hour) against your trimester? Run our glucose target zone calculator first, then come back and use this chart as your reference card.

Get a free printable GD levels chart plus a meal-by-meal tracker built for these exact numbers →

The One Conversion You Actually Need: Multiply by 18

If you only remember one thing from this page, make it this: 1 mmol/L is about 18 mg/dL.

• mmol/L → mg/dL: multiply by 18. (Example: 5.3 × 18 ≈ 95.)
• mg/dL → mmol/L: divide by 18. (Example: 120 ÷ 18 ≈ 6.7.)

The textbook conversion factor is 18.018, but 18 is close enough for reading any chart on your phone in a grocery aisle. US glucose meters report in mg/dL. Canadian, UK, Australian, and most other meters report in mmol/L. So if you read GD advice from a different country than your meter, or your friend in Toronto quotes a "6.5" while your meter shows "117," that factor of 18 is what reconciles them (6.5 × 18 ≈ 117). They're saying the same thing.

This matters more than it sounds. A common panic moment is a US mom reading a Canadian forum, seeing "keep it under 7.8" and thinking her 138 reading is wildly high — when 7.8 mmol/L is 140 mg/dL, and she's actually in range. Convert before you worry.

Why Your Targets Are NOT the Numbers on Your Diagnosis Paperwork

This is the single most confusing thing about GD numbers, and almost nobody explains it clearly. You have two completely different sets of numbers:

Set 1: Diagnostic cutoffs (used ONCE, on your glucose tolerance test)

These are the lines on your oral glucose tolerance test (OGTT) that decided whether you got a gestational diabetes diagnosis at all. They're a one-time gate. On the one-step 75g test used by many providers, a diagnosis is made if you meet or exceed any single one of these (per the StatPearls clinical reference, NCBI Bookshelf):

On the two-step approach (a 50g screen followed by a 100g, 3-hour test), the screen flags you at roughly 130–140 mg/dL (7.2–7.8 mmol/L) depending on the lab, and the diagnostic 100g test uses these thresholds — you need 2 or more at or above to be diagnosed (NCBI StatPearls, GDM screening):

Set 2: Management targets (used EVERY DAY, after diagnosis)

The moment you're diagnosed, those diagnostic cutoffs stop being relevant to your daily life. You switch to the tighter management targets at the very top of this article (fasting <95, 1-hour <140, 2-hour <120 mg/dL). Notice the gap:

• Your 2-hour diagnostic line on the 75g test was 153 mg/dL (8.5 mmol/L).
• Your 2-hour management target is 120 mg/dL (6.7 mmol/L).
• That's a 33 mg/dL difference — and it trips up almost everyone.

Why so much tighter? Because the diagnostic test was asking "does your body struggle with a big glucose load?" Treatment is asking "can we keep your everyday glucose low enough to protect your pregnancy?" The whole point of management is to keep your normal-day numbers well under the level that flagged you. So if you see a 130 at 2 hours and think "well, that's under my diagnosis number of 153, I'm fine" — you're reading the wrong chart. 130 is over your 120 management target.

Confused about which number applies to you? Sign up free and we'll map your provider's targets to a simple daily card →

How to Read Each Number on Your Chart

Fasting: <95 mg/dL (<5.3 mmol/L)

This is your reading first thing in the morning, before you eat or drink anything but water, after at least 8 hours without food. It's often the hardest number to control and the last to come into line, because it isn't about what you ate — it's about how much glucose your liver releases overnight (gluconeogenesis). You can eat a perfect dinner and still wake up at 98.

If your fasting is consistently 96–105 mg/dL (5.3–5.8 mmol/L), the most common first move providers and dietitians suggest is a bedtime snack of about 15g carbs plus protein and fat at 9–10pm — for example, ½ cup cottage cheese with 10 almonds. For many women this lowers fasting by 5–15 mg/dL (0.3–0.8 mmol/L) within a week or two. A minority find it makes fasting worse; if your numbers go up after 7–10 nights, stop. Fasting is also the number most likely to need insulin support, and that's biology — not effort.

1 hour after meals: <140 mg/dL (<7.8 mmol/L)

Start your timer at your first bite, not your last. Blood sugar peaks around 60 minutes after most meals, so the 1-hour check catches your true spike. This is the number that tells you whether a specific meal worked. If your breakfast hit 155, your breakfast had too many fast carbs for your body that morning — adjust that plate next time.

2 hours after meals: <120 mg/dL (<6.7 mmol/L)

Also timed from the first bite. By two hours, a well-handled meal should be heading back down toward your fasting baseline. The catch: the 2-hour reading often captures recovery, not the peak. A woman whose 1-hour is 150 and 2-hour is 110 had a spike she didn't see; a woman whose 1-hour is 132 and 2-hour is 112 didn't. That's why the dietitians at Pregnancy Plate Planner generally prefer the 1-hour reading for most women — but if your provider uses 2-hour targets, follow them. Both are valid; just don't mix the timing and the target.

"By Week": What Actually Changes (and What Doesn't)

People search for a GD chart "by week" expecting the target numbers to shift as pregnancy advances. They don't. Fasting <95, 1-hour <140, and 2-hour <120 mg/dL are the same at week 28 as at week 38. What changes is how hard those targets are to hit, because insulin resistance climbs as the placenta grows.

• Weeks 24–28 (diagnosis window): Most women are tested between 24 and 28 weeks (CDC, About Gestational Diabetes). If you're newly diagnosed here, many women hit target with portion control and a starch swap alone. Numbers are usually the most forgiving they'll be.
• Weeks 28–32: Insulin resistance is rising steadily. The same plate that gave you a 115 can start giving you a 130. This is normal. Tighten carb portions toward the lower end of your per-meal range and add a 15-minute post-meal walk.
• Weeks 32–36: Peak insulin resistance for most pregnancies. This is the most common window for needing to add medication if diet and movement can't hold the numbers. If your fasting or after-dinner readings drift over target most days here, it's the placenta out-producing your pancreas — not you failing.
• Weeks 36–40: For some women, insulin resistance plateaus or even eases slightly; for others it keeps climbing. Keep testing 4× a day right through delivery unless your provider says otherwise.

So a "by week" chart of targets is really a flat line — but a "by week" chart of difficulty slopes upward. Plan for your numbers to creep, and treat a creep as a cue to adjust the plate, not as a moral failing.

The Misinformation to Ignore

Myth 1: "Under 200 is fine." You'll see this because 200 mg/dL is the threshold for diagnosing diabetes in non-pregnant adults on a glucose tolerance test (MedlinePlus, Glucose Tolerance Test). Pregnancy targets are far stricter. A 2-hour reading of 160 would be "normal" for a non-pregnant adult and well over target for you. Never use a general adult glucose chart while you're managing GD.

Myth 2: "If I'm under my diagnosis numbers, I'm controlled." Covered above — your diagnosis numbers (e.g., 153 at 2 hours) are not your management targets (120 at 2 hours). This is the most common reading error in GD.

Myth 3: "One high reading means I failed." A single reading above target after an off-plan meal is data, not a diagnosis of poor control. What your care team watches is the pattern: how many readings in a given slot (fasting, post-breakfast, post-dinner) sit above target across a week or two. One 145 after pizza night is life. Five post-dinner readings over 140 in a row is a signal.

Myth 4: "Just avoid sugar and the numbers fix themselves." Total carbohydrate load and pairing matter far more than added sugar alone. A plain bagel (no added sugar) can spike you harder than a cookie eaten after a protein-rich meal. The chart measures glucose; glucose responds to all carbs, not just the sweet ones. For the food side of this, our 7-day gestational diabetes meal plan is built to keep each meal under these exact targets.

A Worked Example: Reading a Real Day

Here's an actual day's log and how to read it against the chart. Say you're 31 weeks:

Reading this correctly: three of four numbers are in range, and the one miss is breakfast. Breakfast is famously the hardest meal in GD because morning insulin resistance is highest — so this isn't surprising. The move is not to panic about the day; it's to change tomorrow's breakfast: cut the fast carbs (cereal, juice, toast), lead with protein and fat (eggs, cheese), and keep total breakfast carbs to roughly 15–30g. One adjustment to one meal. That's how you use the chart — as a meal-by-meal diagnostic, not a daily report card.

Before You Trust a Number: Get the Reading Right

A chart is only as good as the readings you put against it. A surprising share of "my numbers are all over the place" frustration comes from technique, not biology. Gestational diabetes is monitored with regular blood glucose checks — typically four times a day, fasting plus after meals (NIDDK, Gestational Diabetes) — so small, repeated errors add up fast. Before you decide a reading is "high," rule these out:

• Wash and dry your hands first. A trace of fruit juice, lotion, or sugar on a fingertip can throw a reading off by 10–30 mg/dL (0.5–1.7 mmol/L) — enough to turn an in-range number into a "fail." Plain water, then dry; skip the alcohol wipe unless you have no sink, because residual alcohol skews readings too.
• Use the side of your fingertip, not the pad. It hurts less and tends to give a cleaner sample. Use a fresh lancet often; a dull one needs squeezing, and over-squeezing dilutes the drop with tissue fluid and lowers the reading.
• Don't test on a cold or just-washed-in-hot-water hand. Temperature changes blood flow at the fingertip and can shift the number. Let your hand return to normal temperature first.
• Check your strips. Expired or heat-damaged strips drift. Keep the vial closed, out of the bathroom (humidity), and out of a hot car. Match the code on the vial to your meter if your meter uses coding.
• Be consistent about timing. A meter doesn't know whether you started your timer at the first bite or the last. Pick first-bite and stick to it, or your post-meal numbers won't be comparable from day to day.

If a single reading looks shockingly out of pattern — a 175 when you usually run 120s after that meal — wash, dry, and retest before you act on it. One clean confirmation is worth more than one alarming surprise. Home meters are also allowed a margin of error of roughly 15% under accuracy standards, so a "138" might truly be anywhere from about 117 to 159; that's another reason to trust the weekly pattern over any single point.

What to Do This Week

1. Confirm your provider's testing schedule and timing. Are you on 1-hour or 2-hour post-meal targets? Write the matching number on a sticky note on your meter: 140 (7.8) for 1-hour, or 120 (6.7) for 2-hour. Fasting is <95 (5.3) either way.
2. Log every reading with what you ate. A number alone ("138") is useless to your care team. "138 one hour after oatmeal and juice" tells them exactly what to change. Pattern over points.
3. Test from the first bite. Set a phone timer when you start eating, not when you finish. A 20-minute meal eaten slowly can otherwise turn your "1-hour" reading into a 40-minute reading and throw off the whole picture.
4. Look for the pattern, not the panic. At the end of the week, count how many readings in each slot were over target. If one slot (say, post-dinner) is over more than 2–3 times, that's the meal to fix. If it's over most days even after you adjust, that's the conversation to have with your provider.
5. Keep your diagnosis paperwork in a different mental folder. Those OGTT numbers did their job. Manage to the daily chart now.

Diabetes during pregnancy is managed with diet, physical activity, and — for about 1 in 3 women — medication, all aimed at keeping your glucose in the target range (MedlinePlus, Diabetes and Pregnancy). The chart is just the scoreboard. The food, the timing, and the post-meal walks are how you move the score.

The Bottom Line

Tape this to your fridge: fasting <95 mg/dL (<5.3 mmol/L), 1-hour <140 mg/dL (<7.8 mmol/L), 2-hour <120 mg/dL (<6.7 mmol/L). Those numbers don't change with the weeks — your insulin resistance does, so expect the same plate to read higher later in pregnancy and adjust accordingly. Don't compare today's reading to your diagnosis cutoffs, don't compare it to a non-pregnant chart, and don't let one high number undo a good week. Read the pattern. Convert with the factor of 18 if your sources use a different unit. And when a slot stays over target despite plate changes, that's exactly the data your provider needs to help you fast.

For the deeper "why" behind these targets and how they connect to your management plan, see our complete guide to blood sugar targets for gestational diabetes.

Ready to stop guessing and start hitting these numbers? Join Pregnancy Plate Planner free — get the printable levels chart, a meal-by-meal carb-and-protein tracker, and weekly meal plans built to keep every reading under target →