How-to · Educational, not a prescription · Updated October 2, 2026
How do you read a sliding scale insulin chart?
Direct answer
Find the blood-sugar row and give the rapid- or short-acting units written there. On this moderate example, 247 mg/dL is 4 units (the 201–250 mg/dL row, 11.2–13.9 mmol/L). Below 70 mg/dL, give none. A written order replaces this example.
Example chart: 1, 2, or 3 units per 50 mg/dL above 150
| mg/dL | mmol/L | Low | Moderate | High |
|---|---|---|---|---|
| <70 | <3.9 | Hold | Hold | Hold |
| 70–150 | 3.9–8.3 | 0 u | 0 u | 0 u |
| 151–200 | 8.4–11.1 | 1 u | 2 u | 3 u |
| 201–250 | 11.2–13.9 | 2 u | 4 u | 6 u |
| 251–300 | 14.0–16.7 | 3 u | 6 u | 9 u |
| 301–350 | 16.8–19.4 | 4 u | 8 u | 12 u |
| 351–400 | 19.5–22.2 | 5 u | 10 u | 15 u |
| >400 | >22.2 | 6 u | 12 u | 18 u |
Total daily insulin under about 40 units, older or thin adults, kidney disease, not eating. Total daily insulin about 40–80 units, typical adult eating meals. Total daily insulin over about 80 units, obesity, steroids, infection. These bands are the calculator’s teaching charts, built as whole units per 50 mg/dL above 150.
247 mg/dL on the moderate chart
247 mg/dL is 13.7 mmol/L. It sits in 201–250 mg/dL (11.2–13.9 mmol/L), so the moderate chart says 4 units. The low chart says 2 units and the high chart says 6 units for the same row. Because the reading is above 240 mg/dL, the calculator also flags a ketone check for type 1 diabetes or illness. Above 240 mg/dL (13.3 mmol/L): check blood or urine ketones if you have type 1 diabetes or are unwell. Moderate or large ketones need same-day medical advice.
Limits
- This is not an insulin order. Dose, insulin type, and timing come from the prescriber’s chart.
- ADA Standards of Care 2026 discourage using a correction scale without basal insulin for most people in hospital.
- Below 70 mg/dL, give no correction insulin. Above 400 mg/dL, the top row says to give the ordered dose and call the prescriber.
Use the calculator
A personal correction factor: how the 1800 rule works. Look up a reading in the insulin sliding scale calculator.