Why this calculator exists
The interesting fact about Lipa Mdogo Mdogo, at least on the Itel A60 tier where Safaricom's T&Cs disclose the split, is that the KES 100 daily instalment is roughly KES 45 device + KES 55 compulsory bundle. That means the device credit is nearly free (the KES 45 daily x 366 days approximately equals the KES 18,300 cash price) and the buyer is really paying for a year of bundled data and airtime at KES 20,130.
Whether that bundle is a good deal depends entirely on what you already spend on connectivity. If you burn through KES 50 to KES 70 per day on data anyway, the bundle is inside what you would spend and Lipa Mdogo Mdogo effectively delivers a phone at cash price with the connectivity absorbed. If you use very little data, the bundle is money you would not otherwise spend and you are being pushed to overpay.
How the calculator scores it
The tool multiplies your monthly data plus voice plus SMS by 12 to get your annual connectivity spend. It compares that against the verified bundle annual (KES 20,130 for the Itel A60 tier). If your annual spend meets or exceeds the bundle, the verdict is "reasonable value". Otherwise the verdict shows the overpayment gap in KES per year.
Why other tiers show a warning
The Neon Smarta, Itel A24, Neon Ultra and Tecno Pop 7 do not have a published device/bundle split in the 2024 Safaricom T&Cs. Extrapolating the same ratio to them would be speculation. When those tiers are selected the tool refuses to compute and explains why.