Step by Step
How to use it
Five inputs, one result — takes under 30 seconds.
1
Select Product Shelf Life
Choose 18, 24, 30, or 36 months. This is the shelf life of the specific product you are calculating for. Run the calculator separately for each product in your order.
2
Choose Shipment Mode
Select Air or Sea. Air transit defaults to 7 days; sea to 45 days.
3
Adjust Transit Days (if needed)
The transit field is editable. If your actual route takes more or fewer days, tap it and type the correct number.
Tip: Defaults cover most routes — only change if you know the exact transit time.
4
Set Customer Requirement
Enter what the customer says they need at their warehouse. Use % mode if they gave you a percentage (e.g. "75%"), or Months mode if they said months remaining (e.g. "6 months"). Both give the same result.
Use Date mode when the customer gives a required delivery date — the date they need stock at their warehouse (common in tenders and POs). Pick the planned manufacturing month and enter that date; the calculator subtracts your transit days to find when stock must leave VGFC, then shows the required VGFC%.
5
Read the Result & Enter in SpineNextGen
The big number is what to type into the shelf life % field in SpineNextGen. Tap it to copy. Check the colour indicator to confirm the shipment is feasible before proceeding.
Glossary
Key terms explained
Input
Product Shelf Life
The total shelf life assigned to this product at manufacture (e.g. 24 months from date of manufacture). If your order contains multiple products with different shelf lives, run the calculator separately for each product.
Input
Customer Requirement
What the customer says they need at their warehouse. Enter it as a percentage of total shelf life, as months remaining, or — in Date mode — as the required delivery date by which they need the stock. Use whichever format the customer gave you; all three feed the same VGFC% result, with transit always accounted for.
Input
Shipment Mode
How the goods will travel. Air is faster (~7 days, higher cost). Sea is slower (~45 days, lower cost). The mode determines how many days of shelf life are consumed in transit.
Input
Transit Days
The number of days goods spend travelling from VGFC dispatch to the customer's warehouse. Defaults to 7 (air) or 45 (sea) — editable if your route differs. For multi-hop chains (e.g. goods that pass through a distributor before reaching a health authority), set this to the total time from VGFC dispatch to the final delivery point — shipping days plus any intermediate holding time.
Output
VGFC % (the result)
The shelf life percentage to enter into SpineNextGen. It represents how much shelf life must remain at VGFC at the time of dispatch — which is the customer's requirement plus the percentage consumed during transit.
Output
Months at VGFC
The VGFC % converted to months, shown below the big percentage. This is an approximate equivalent to help cross-check — the SpineNextGen field uses the percentage, not the months.
Output
[Month] manufacturing
In % and Months modes this shows the oldest acceptable manufacturing month — any batch made in this month or later meets the customer's requirement. In Date mode you set the manufacturing month yourself with the slider (it can't be later than the date stock must leave VGFC). Either way, use it to coordinate with production on which batches to allocate.
Convention
Expiry Date (Pharma Convention)
The calculator uses the regulatory pharma convention for expiry dates:
Manufacturing date = the 1st day of the manufacturing month, regardless of the actual day the batch was made. A batch manufactured on 17 Aug 2026 is treated as manufactured 1 Aug 2026.
Expiry date = the last day of the month before the shelf-life anniversary. Count S months forward from the manufacturing month, then step back one month and take the last day. For example: Manufactured Aug 2026, S = 24 mo → anniversary = Aug 2028 → expiry = 31 Jul 2028 (not 31 Aug 2028).
This convention is used in Date mode to calculate what fraction of total shelf life remains at VGFC dispatch.
Manufacturing date = the 1st day of the manufacturing month, regardless of the actual day the batch was made. A batch manufactured on 17 Aug 2026 is treated as manufactured 1 Aug 2026.
Expiry date = the last day of the month before the shelf-life anniversary. Count S months forward from the manufacturing month, then step back one month and take the last day. For example: Manufactured Aug 2026, S = 24 mo → anniversary = Aug 2028 → expiry = 31 Jul 2028 (not 31 Aug 2028).
This convention is used in Date mode to calculate what fraction of total shelf life remains at VGFC dispatch.
Reading the Result
What the colours mean
The result card changes colour to tell you if the order is feasible. A text label inside the card also shows the status — useful when the colours are hard to distinguish.
✓ Feasible — Good to go
Result below plant threshold (88–94%, depending on shelf life)
The shelf life requirement can be met and the plant has at least 2 months of manufacturing lead time. Proceed with this product.
- Shelf life
- Plant threshold
- 18 months
- Below 88%
- 24 months
- Below 91%
- 30 months
- Below 93%
- 36 months
- Below 94%
⚠ Tight — verify with production
Result at or above plant threshold – 100%
The requirement leaves less than 2 months for plant manufacturing, procurement, and QC. Before confirming: consider switching to Air shipment (fewer transit days lower the required VGFC %), revise order terms with the customer, or check with production — if a batch is already in quarantine or QC, lead time may be only 15–30 days.
✗ Not feasible
Result > 100%
The transit time makes this shipment impossible at the customer's requirement. Switch to air shipment (shorter transit = lower VGFC %) or discuss a lower shelf life requirement with the customer.
Scenarios
Worked examples
Find your situation below to see exactly what to enter.
Direct
Customer specifies a shelf life percentage
Your customer says they need 75% shelf life remaining at their warehouse. You're shipping by sea, 24-month product.
Enter: Shelf Life = 24 mo · Shipment = Sea · Transit Days = 45 · Customer Requirement = 75%
Result: 81% — enter this in SpineNextGen.
Enter: Shelf Life = 24 mo · Shipment = Sea · Transit Days = 45 · Customer Requirement = 75%
Result: 81% — enter this in SpineNextGen.
Multi-hop
Goods travel via a distributor to a health authority
Your customer (distributor) receives the goods and holds them for ~75 days for billing and regulatory clearance before forwarding to the health authority. The health authority requires 75% shelf life on receipt. Shipping from VGFC to distributor takes 30 days.
Enter: Transit Days = 105 (30 days shipping + 75 days holding) · Customer Requirement = 75%
Result: 89% — enter this in SpineNextGen. The transit days field absorbs the full chain, not just shipping.
Enter: Transit Days = 105 (30 days shipping + 75 days holding) · Customer Requirement = 75%
Result: 89% — enter this in SpineNextGen. The transit days field absorbs the full chain, not just shipping.
Tender / Date
The customer gives a required delivery date
A tender requires delivery to the customer's warehouse by 24 June 2026. You plan to ship a batch manufactured in April 2026 by sea (45 days), 24-month product.
Enter: Date mode · Manufacturing month = April 2026 · Customer Required Date = 24 Jun 2026
The calculator uses these dates:
• Manufactured: 1 Apr 2026 (1st of the manufacturing month)
• Expiry: 31 Mar 2028 (last day before the Apr 2028 anniversary; S = 24 mo)
• Leaves VGFC: 10 May 2026 (24 Jun − 45 days transit)
VGFC% = (31 Mar 2028 − 10 May 2026) ÷ (31 Mar 2028 − 1 Apr 2026) × 100 = 95% — enter this in SpineNextGen.
Enter: Date mode · Manufacturing month = April 2026 · Customer Required Date = 24 Jun 2026
The calculator uses these dates:
• Manufactured: 1 Apr 2026 (1st of the manufacturing month)
• Expiry: 31 Mar 2028 (last day before the Apr 2028 anniversary; S = 24 mo)
• Leaves VGFC: 10 May 2026 (24 Jun − 45 days transit)
VGFC% = (31 Mar 2028 − 10 May 2026) ÷ (31 Mar 2028 − 1 Apr 2026) × 100 = 95% — enter this in SpineNextGen.
Not Feasible
Result is over 100%
Sea transit is consuming too much shelf life for this combination. Two options:
1. Switch to Air — reduces transit to ~7 days, which usually brings the result below 100%.
2. Negotiate with the customer — ask if they can accept a lower shelf life requirement, allow a later delivery date, or supply a fresher (later) manufacturing batch.
1. Switch to Air — reduces transit to ~7 days, which usually brings the result below 100%.
2. Negotiate with the customer — ask if they can accept a lower shelf life requirement, allow a later delivery date, or supply a fresher (later) manufacturing batch.
FAQ
Common questions
Sea transit is too long for this combination. Try switching to Air — the shorter transit time usually brings the result down to a feasible level. If air is also not feasible, you'll need to discuss accepting a lower shelf life requirement with the customer.
Run the calculator separately for each product using that product's shelf life. For example, if the order has an 18-month product and a 24-month product, calculate the VGFC% for each one individually and enter them separately in SpineNextGen.
They calculate the same result — just different ways to enter the customer's requirement. Use % mode when the customer says something like "I need 75% shelf life." Use Months mode when they say "I need at least 6 months remaining." Switch using the toggle above the slider.
Yes. The Transit Days field is editable. Tap or click on it and type in the actual number of days for your route. The calculation updates instantly. The field accepts values between 1 and 180 days.
Sea transit takes about 38 more days than air (45 vs 7). Every extra day in transit is shelf life the customer won't receive — so the calculator adds more to the VGFC % to compensate. The longer the transit, the higher the result.
Tap or click anywhere on the result card (the big percentage). The copy button confirms with "Copied 95%" and the number lands on your clipboard — paste it directly into SpineNextGen.
Yes. The calculator is a single HTML file with no server dependency. Once the page has loaded, it works entirely in your browser — no internet connection required for calculations.
It means any batch manufactured in February 2026 or later has enough shelf life to meet the customer's requirement. This is shown in all modes (%, Months, and Date). Use it when coordinating with production on which batches to allocate: any batch from that month onwards — including this month or future months — is acceptable.
The Transit Days field covers all time from VGFC dispatch to the final shelf-life checkpoint — not just shipping. Add every leg together: shipping days to the distributor + the number of days the distributor holds the goods. Example: 30 days shipping + 75 days holding = enter 105 as Transit Days. Then set Customer Requirement to the health authority's minimum (e.g. 75%). The result is the correct VGFC% for the entire chain.
Switch to Date mode. Set the manufacturing month of the batch you plan to ship, then enter the customer's required delivery date. The calculator subtracts your transit days to find when stock must leave VGFC, and shows the VGFC% to enter in SpineNextGen. The manufacturing month can't be later than the dispatch date — the slider caps automatically so you can't pick an impossible batch.
Yes — indirectly. The slider maximum is set one month short of 100% VGFC (which would mean manufacturing today and dispatching instantly — not operationally possible). At the slider's rightmost position the manufacturing month shown is typically the previous month, but the “[Month] manufacturing” label means that month or any later month — so if March is shown, April and beyond are all acceptable too. Any batch manufactured this month or in future months will comfortably meet the requirement.
It follows the standard regulatory pharma convention. Two rules apply:
Manufacturing date: always treated as the 1st of the manufacturing month, regardless of the actual production day. A batch made on 17 Aug 2026 is counted from 1 Aug 2026.
Expiry date: count the shelf-life months forward from the manufacturing month, then take the last day of the month before that anniversary. So for a 24-month product manufactured in Aug 2026: the anniversary is Aug 2028, and the expiry is 31 Jul 2028 — not 31 Aug 2028.
Why one month earlier? Regulatory convention treats the batch as manufactured on the 1st of the month. The "anniversary" 24 months later falls on 1 Aug 2028, so the batch has not completed its 24th month until that date arrives. The last valid date before that — when the full shelf life has been enjoyed — is the last day of the preceding month, 31 Jul 2028.
Manufacturing date: always treated as the 1st of the manufacturing month, regardless of the actual production day. A batch made on 17 Aug 2026 is counted from 1 Aug 2026.
Expiry date: count the shelf-life months forward from the manufacturing month, then take the last day of the month before that anniversary. So for a 24-month product manufactured in Aug 2026: the anniversary is Aug 2028, and the expiry is 31 Jul 2028 — not 31 Aug 2028.
Why one month earlier? Regulatory convention treats the batch as manufactured on the 1st of the month. The "anniversary" 24 months later falls on 1 Aug 2028, so the batch has not completed its 24th month until that date arrives. The last valid date before that — when the full shelf life has been enjoyed — is the last day of the preceding month, 31 Jul 2028.
The plant needs a minimum of ~2 months from order confirmation to batch availability — time for incoming API and materials receipt, QC approval, manufacturing, and testing. Two months represents a different fraction of total shelf life depending on the product: it is a larger slice of an 18-month product's life than a 36-month product's. The calculator converts this fixed lead time into a percentage using the formula
100 − (2 ÷ shelf life months × 100), floored to the nearest whole number. This gives the threshold at which the plant's lead time starts to be squeezed — 88% for 18-month products, 91% for 24-month, 93% for 30-month, and 94% for 36-month. Results below this threshold are green; at or above are orange.